0ne hybridized combinations between 2 self lines as parents with different budding period were used to analyze the inheritance of budding period in their progeny family groups P1,P2,F1,B 1,B2 and F2 by utilizing the method of joint segregation of major genes plus polygenes.The results showed that budding period in the cross of y145 × b145 was controlled by two major genes with additive-dominant-epistatic effects.The heritability of the major gene was 47.22 % in B1 generation,37.95 % in B2 generation,and 46.45 % in F2 generation.The major gene effects was important and should be utilized effectively in the breeding program.The improvement of budding period trait should be selected in middle and high generation.