Chang was born on October 10, 1908, in the village of Dunhòu (敦厚), which lies 64 miles (103 km) northwest of Taiyuan, the capital city of Shanxi province, in Qing dynasty China.

[1] His family was able to provide for him a good education, and in 1933, he obtained a bachelor's degree in animal psychology from Tsinghua University in Beijing.

[2] On an invitation from Arthur Walton, Chang left the University of Edinburgh and went on to research ram spermatozoa at Fitzwilliam College, Cambridge.

[2] Chin assumed the role of the housewife in the pair's marriage, allowing Chang to delve into his work without domestic concerns.

[2] One of Chang's notable achievements was his research and testing of the effectiveness of certain orally administered steroids in the control of mammalian fertility.

Chang is arguably most remembered for this endeavor as the birth control pill came to have a tremendous influence on human society and the sexual revolution.

The process of capacitation, the maturation period of sperm that is required in order for them to be able to fertilise ova, was also one of Chang's major discoveries.

In the years that followed, Chang and his associates conducted further research to determine specific conditions of successful in vitro fertilisation as well as to perform the technique on other mammals such as hamsters, mice, and rats.

It was on the basis of Chang's findings that the first in vitro fertilisation of human eggs was performed, leading to the birth of the world's first "test tube baby" in 1978.