Abstract: Yield components of two different winter wheat varieties in the Hexi irrigated area of Gansu were analyzed through all, 1/3, 1/2 tiller and main-stem removal and the control (CK), labelled as A, B, C, D and E respectively. The results indicate that total biomass and effective tiller weight of the two winter wheat varieties under treatments B and D are higher than under CK. Compared with CK, though main-stem spike length, spike weight, per-spike grain number and grain weight are highest in treatment A, there is no remarkable difference in these variables among treatments. Tiller spike length, spike weight, per-spike grain number and grain weight in treatments B and D are higher than in CK, but those in treatments A and C are lower than in CK. We therefore conclude that at least 1/3 tiller is redundant for winter wheat cultivation in Hexi area of Gansu.