Abstract: Bird song behavior is an important function for birds to attract their spouse and protect their territories. However, the related researches concentrate in male, especially for the birds of sexual dimorphism, and often neglect female. The song of many females also has the roles of preventing territories and attracting the opposite sex. Some of female song can form duet with male song. This paper reviewed the researches on the bird duet and female song behaviors, and approached their functions and adaptability.