A study was made on early, normal and delayed planting dates on the seed yield and its components of two late varieties of soybean, UFV-1 and IAC-7. The field experiment was carried out at Campinas Experimental Station in eutrophic Latossolo Roxo during the years 1979/80 and 1980/81. In the first year planting were made every twenty days starting from October 5 and in the second year every thirty days starting from September 17, the total being eight and seven in the consecutive years. The parameters studied were: seed yield, nodes/ /plant, podes/plant and seed weight. The planting dates affected the seed yield and its components in both varieties. The number of nodes and pods/plant were more affected than the seed weight. Each variety had the same behavior with regard to the number of nodes and pods/plant and the same cannot be said to seed weight. In the first year the seed weight was not affected by the planting date and in the second, late plantings decreased the values of this parameter. The variability of yield components was more effective for highest yields planting dates. Number of nodes and pods/plant exercised a greater influence on the seed yield than the seed weight.