For investigating the linkage group to which the semidwarf gene sd-t belongs, the crosses between Aitaiyin 2(ATY2), a variety of sd-t carrier in indica rice, and marker stocks as well as the trisomic lines of IR36 were made. The results indicated that the sd-t gene was linked to the marker genes Prp-b (Purple pericap b), lg(ligueless) and Wh(White hull). The recombination values estimated were 2.85% +/- 0.52% for sd-t to Prp-b, 27.90% +/- 3.81% for sd-t to lg and 38.62% +/- 2.99% for sd-t to Wh, respectively. It was inferred that the sd-t gene was located on chromosome 4 according to the established relationship between chromosomes and linkage groups.