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Reciprocal sets of chromosome substitution lines bçtween two hard red winter wheat cultivars, Cheyenne and Wichita, were used to identify chromosomes that carry genes for heading date. The material were planted in the pots, using a completely randomized design with two replications. Heading dates were recorded when 50% of plants in a pot had their spikes emerged. Heading date was considered as the number of days from an arbitrary date to the time of heading. Analysis of variance of the data showed that Wichita appears to carry genes controlling heading date on chromosmes 3A, 3D and 1D,while Cheyenne carries genes on 3A,3D 1D, 4D, 6A and lB. The genes from Wichita accelerated heading date of Cheyenne and those from Cheyenne delayed heading date of Wichita.Reciprocal substitution chromosomes 1B, 6A and 4D from Wichita into Cheyenne had no significant effect on Cheyennes heading date. This may indicate that Wichita does not carry genes for earliness on 1B,6A and 4D chromomes, or has genes with minor effects