From The Art and Popular Culture Encyclopedia
I Ching (The Book of Changes) is a book of Chinese literature. It deals with what would be in the West termed metaphysics. In it, sexual intercourse is one of two fundamental models used to explain the world. With neither embarrassment nor circumlocution, Heaven is described as having sexual intercourse with Earth. Similarly, with no sense of prurient interest the male lovers of early Chinese men of great political power are mentioned in one of the earliest great works of philosophy and literature, the Zhuang Zi (or Chuang Tzu, as it is written in the old system of romanization).
China has had a long history of sexism, with even moral leaders such as Confucius giving extremely pejorative accounts of the innate characteristics of women. From early times, the virginity of women was rigidly enforced by family and community and linked to the monetary value of women as a kind of commodity (the "sale" of women involving the delivery of a bride price). Men were protected in their own sexual adventures by a transparent double standard. While the first wife of a man with any kind of social status in traditional society was almost certainly chosen for him by his father and/or grandfather, the same man might later secure for himself more desirable sexual partners with the status of concubines. In addition, bondservants in his possession could also be sexually available to him. Naturally, not all men had the financial resources to so greatly indulge themselves.
Chinese literature displays a long history of interest in affection, marital bliss, unabashed sexuality, romance, amorous dalliances, homosexual alliances -- in short all of the aspects of behavior that are affiliated with sexuality in the West. Besides the previously mentioned Zhuang Zi passages, sexuality is exhibited in other fine works of literature such as the Tang dynasty Yingying zhuan (Biography of Cui Yingying), the Qing dynasty Fu sheng liu ji (Six Chapters of a Floating Life), the delightfully and intentionally salacious Jin Ping Mei, and the incredibly multi-faceted and insightful Hong lou meng (Dream of the Red Chamber, also called Story of the Stone). Of the above, only the story of Yingying and her de-facto husband Zhang fail to describe homosexual as well as heterosexual interactions. The novel entitled Rou bu tuan (Prayer mat of flesh) even describes cross-species organ transplants for the sake of enhanced sexual performance. Among Chinese literature are the Taoist classical texts.  This philosophical tradition of China has developed Taoist Sexual Practices which have three main goals: health, longevity, and spiritual development.
The desire for respectability and the belief that all aspects of human behavior might be brought under government control has until recently mandated to official Chinese spokesmen that they maintain the fiction of sexual fidelity in marriage, absence of any great frequency of premarital sexual intercourse, and total absence in China of the so-called "decadent capitalist phenomenon" of homosexuality. The result of the ideological demands preventing objective examination of sexual behavior in China has, until very recently, made it extremely difficult for the government to take effective action against sexually transmitted diseases, especially AIDS. At the same time, large migrations to the cities coupled with significant amounts of unemployment have led to resurgence of prostitution in unregulated venues, a prominent accelerant of the propagation of STDs to many ordinary members of society.
In recent decades the power of the family over individuals has weakened, making it increasingly possible for young men and women to find their own sexual and/or marriage partners.