The genetic behavior of green cotyledon character in soybean Dandou 6was researched.the green and yellow color cotyledon seeds were investigated in the F2、F3and F4segregative generations of Kefeng14×Dandou 6and Yi1358×Dandou 6.The results showed the yellow cotyledon seeds and green cotyledon seeds in two progenies were accord to Mendel's single gene inheritance model,and a recessive gene control the green color cotyledon in Dandou 6.