Abstract: Three physical treatments viz. Sand paper scraping, beating and hot water treatments and two chemical treatments viz. Concentrated sulphuric acid and ethyl alcohol were included in the study. These treatments were applied on seeds of two sizes viz. large and small. Results of the experiments revealed that sand paper scraping and concentrated H2504 showed more effective performance than beating and hot water treatments in breaking seed dormancy of Sesbania rostrata. Ethyl alcohol had no effect on breaking seed dormancy. Large seed showed lesser dormancy than small one. Sand paper scraping 113 revolutions) of large seed gave the highest germination (97.8%).