The main cultivated varieties belonged to the species of Upland cotton (Gossypium hirsutum L.) in the world and their genetic background is very narrow.However,the wild species and race in the genus of Gossypium have abundant genetic diversity and possess lots of excellent genes with potential high yield,fine and strength fiber,disease and insect resistance,drought and coldness resistance,male sterility and so on.The interspecific hybridization for utilizing the benefit genes from these wild tetraploid species had been widely carried out for 20 years in China.