Throughout thousands of years，successfully domesticated crop plants have gone through longtime courses of continuous cultivation and selection. This principal has been validated in earlier domesticated crops such as wheat，corn，rice，apple，plum and grape，and in kiwifruit，blueberry and strawberry which were domesticated in a relative duration. By history as reference，this paper briefly outlines and analyzes the processes of domestication and genetic improvement of plant crops. Meanwhile，we focuses on cases of the fruit trees that are domesticated last century，and discusses the principal and strategy for domesticating wild fruit species in the 21th century.