I'm mostly basing this off my notes in my "Women's Roles in the Chinese Revolution" class, although you can see the effects of societal changes in the autobiography A Woman Solder's Own Story by Xie Bingying.

Some historical context:

China in the early 1900s was full of intellectuals, both reformers and revolutionaries. Both groups were concerned with the state of China, which they saw as weak against the Western powers (and how could they not, after the Opium Wars and the unequal treaties, as well as the spheres of influences imposed by Western powers?). As such, the discussion at the time was concerned with how to resolve China's weakness.

Now how does this relate to women?

Women were seen the symbol of China's weakness. Chinese women at the time were expected to follow Confucian traditions of the three followings (following husband, sons, and mother), to be chaste and faithful to her husbands, and to obey her mother in law. Men were able to take a wife as well as several concubines. Marriages were arranged by a matchmaker between families, in many cases when the prospective spouses were babies or toddlers, and the young girls can sometimes be sent to live with her mother in law for several years before her marriage (little-daughter-in-law). Women, for the most part, were not educated. The practice of foot binding was widespread at the time. Etc. Because these all differed from Western traditions (which, among other things, emphasized love marriages and monogamy), the state of the Chinese woman was seen as backwards. By adopting Western traditions and liberating Chinese women from the home, it was believed that China would become a stronger state. Early movements at women's emancipation included the anti-footbinding movement, and the rise of schools for women and girls.

The anti-footbinding movement sought to, well, unbind women's feet. The first anti-footbinding society was founded in 1883 by Kang Youmei (who would later be appointed by the Qing Dynasty to try to reform the country; his recommendation was to abolish the practice of footbinding). Bound feet were treated by doctors in Japan to loosen the muscles and eventually get the feet to be as close as natural as possible. Families were encouraged to not bind their daughters' feet; anti-footbinding societies served as places for families to arrange marriages to assure parents that their daughters will be married off, even with unbound feet. Anti-footbinding societies would also promote educating girls, and when Liang Quichao founded a girls' school in 1898, only women with natural or unbounded feet were allowed to attend. The practice finally disappeared in the 1930s.

The other major arm for women's emancipation is educating women. There were three types of schools: missionary (run by Christian missionaries), private, and government run. These tend to be concentrated in urban areas, where Western influences were strongest. The first girls' school (a missionary school) opened in 1884. Xie Bingying, whose autobiography I mentioned earlier, went on a hunger protest against her mother for the opportunity to study at her local private school. Although not many women were able to attend schools (with around 4000 women enrolled in 1914), this was seen as liberating for women.

Now then. How does this relate to the Republic of China?

After the fall of the Qing Dynasty in 1911, the New Cultural Movement rose. The New Cultural Revolution sought to strengthen China by advocating individualism, women's rights, science, and democracy. They believed that Confucian traditions as the source of China's problems and sought to abolish it. Their leading periodical, New Youth, was edited by the leading intellectuals of the day: Chen Duxiu (who would later find the Chinese Communist Party), Hu Shi (the most moderate of the three), and Lu Xun. During this time, women became more prominent in Chinese society. The more politically aware women would seek love marriages over arranged marriages, and more women began to be more educated. Women began to take part in politics, as seen in the May Fourth Movement in 1919; the May Fourth Movement was the first protest in which women were able to participate and take part, and exemplified the New Woman advocated by the New Cultural Movement.

One should note that most advocates for women's emancipation were men, and that most of this liberation occurred in urban areas. Rural areas were not as likely to see change. However, this is a shift from previous thoughts on gender relations and equality.

The Nationalists in power would also take part in social reform. The 1930 civil code would abolish patrilineal succession, which would allow women equal rights to inheritance. In addition, the 1931 family code would abolish concubines and bigamy, and allowed women to seek divorce from her husbands (although not no-fault divorce).

The CCP also took part in social reform and advocated a woman's choice in marriage and women's economic independence (which required women to be educated; this was seen as a way for women to be equal to men). They issued a document called "Marriage Relations" in 1921 and "Marriage Laws" in 1931, which also allowed women to seek divorce from her husband. These would have effects on areas controlled by the CCP (which was outlawed by the Nationalist Party in 1927). But the CCP wouldn't push these policies on the peasants, as many peasant men were unhappy that their wives could divorce them, and their support mostly came from the peasants.

I hope this helps answer your question a bit.