Occurrence of chalkiness is a major problem as it is an important parameter in determining quality of rice grains. High temperature during the grain filling period results in loose packing starch granules that could be due to involvement of starch degrading enzymes i.e., amylases. Therefore, two rice genotypes viz., PAU 3699-13- 2-1- 1 and PR122 were sown at two different dates. Thirty- day old seedlings of the two genotypes were transplanted in the field at two different times in order to expose the plants to different temperature regimes during grain filling. A Significant increase in total amylase activity was observed during early transplanting. The chalky genotypes i.e., PAU-3699- 13-2- 1-1 possessed higher α-amylase activity than translucent genotype (PR122) during heat stress. Whereas, PR122 possessed higher β amylase activity than PAU-3699- 13-2- 1-1. High temperature encountered during early transplanting resulted in induction of activities of amylases.