I think the author did something really cool with this book, but I can find no evidence that anyone agrees with me, so you might want to crib info from a more reliable source if you have to write a book review on this thing for your high school English class. The author was the offspring of Christian missionaries and she grew up in China. I assume that she had access to at least some English language novels. I think that she took OT/Tanakh conceptions of a Good Wife (like here: https://www.biblegateway.com/passage/?search=Proverbs%2031:10-31&version=NRSV), English novels about the rise and fall of Great Houses/Families, and the view of China she got growing up with her parents and traveling around China with her husband, and braided them into a story of how a family arose from the "earth" -- a common farmer and the wife he bought out of the rich House of Hwang where she had been a servant for a decade or more, sold as a 10 year old -- prospered briefly through hard work, suffered due to expectable natural events, made their own luck in the chaos of war by stealing from some exceptionally short-sighted rich people in the city to which they fled, returned to their land and then used all their hard won wisdom to elevate their family to displace the rich House of Hwang.
Real families and fictional families tend to both be built on the extremely strong backs and hard labor -- in every sense of the term -- of the oppressed women within them who get little credit and who watch their children feel contempt for their ignorance, exhaustion and old fashioned morals. A striving family which is rewarded with success launches its offspring into the literate professions that don't have to work, or not as hard, or not outdoors (Jewish, English or Chinese). Buck ably depicts that even if that generation keeps its act together and stays away from dissipating habits and bad companions, eventually a generation will come along that gives in to grasping women who offer their beauty and sexual skills in exchange for all that hard won valuta. Or to opium. Or paying too much attention to social status and spending all the dough on the house and parties and so forth. And even if you can be very clever and build your house on stilts for the floods and keep enough grain to tide you over a bad year or two, it is very difficult to protect what is yours from bandits and war. The good will of those far less well off than you (now, anyway) becomes important, and constrains the frugality that enabled the family to Rise Above, lest they decide that all the money is being hoarded and not spent and circulating as it should do.
It's an incredibly depressing read, however, because the depth of poverty is truly striking. The setting is not so long ago (there are trains for the trip from the village to the city when drought leads to starvation), yet this family and many others are too poor -- at least initially -- to have a pig (actually, that's so amazingly poor the mind really boggles). The degrees of starvation are described in excruciating detail and include at least implied if not actual cannibalism (not by the central nuclear family, but by others). Some of the Wang family's success derives from O-lan's (the mother) experience in an earlier family in which she was sold so the rest of the family could survive. O-lan remembered how to beg and how to build a shelter from mats in the city; she cannily anticipated the chaos that would occur when the army arrived in the city and bet their survival that they could come out of it both alive and ahead.
Anyone whose benchmark for scratching a living out of the land while poor comes from a Western European or American context has embedded in them a set of assumptions about draft animals and food animals and so forth. Those animals are (with the exception of oxen for plowing) wildly absent in the Chinese context: pigs and chickens are things only the comparatively well-off have, and the rich get around town with human-powered vehicles rather than horse or mule drawn. In case you missed the obvious message, Pearl Buck will tell you straight out, when Lung attempts to bring rice from the charity kitchen out of the charity facility. Nope, you can't do that, because other people would fatten animals with the food. The idea is clearly repulsive all around, and that priority given to human life over animal life (even when it means infanticide and selling girls into slavery, and adult men acting as beasts of burden) is a little hard to argue with, if difficult to really understand in a world driven by fossil fuels.
It's rare to run across a book that does such a good job of evoking a particular time and place while connecting it to universal themes in a way that feels Real and Believable in a very, very different time and place. And all without bludgeoning you with too much of a moral. I found Lung's fecklessness utterly believable (O-lan was so freakin' wise that she was tougher to really believe in, because she's like the Goddess Incarnate come down to Suffer and show us Wisdom), and loved how his dissatisfaction in conjunction with his somewhat hypocritical and often flexible morality both led to the family's success and caused all kinds of pain for the family. I also loved that this is a book in which significant disability (Lung's desire to avoid a wife with a cleft palate, for example; the older Wang daughter, generally referred to as "my poor fool", who was mute and suffered, at a minimum, some significant cognitive limitations) is depicted -- it's not erased. Some people are awful about it all the time, others only part of the time (O-lan, of course, is just the Best Mom Ever).
I can't _recommend_ the book, simply because reading it was one of the most painful things I've done in the last few years, and if last night was any indication it's gonna be disturbing my sleep on and off for a while yet. But if any book ever deserved to be read and talked over and thought about, this book ought to be considered for that honor.