Abstract: To understand the selection-response of the characters on spike differentiation among different generations by mass selection under temperate, in Guanzhong Plain, Shaanxi province, tropical maize population Mobai 962 was used. The result are as follows: Internal of differentiation phase I, IV and V during tassel development, there is no significantly difference among different generations C0, C2 and C4; there are significant difference at phase II and III between generation C0 and C4. There are significant differences at ear differentiation phase I and II among generations C4 and C0, C2. There are no significant difference about the internal of tassel and ear at the same differentiation phase.