Mutagenic effect of EMS on pollen mother cells of Sesbania cannabina has been investigated in the present cytogeneticalobservation. The progenies were obtained from seeds treated with four different time durations (1, 3, 5, and 7 hours) of 0.5%solution of ethyl methane sulphonate (EMS). Study revealed various types of chromosomal aberrations at different doses ofEMS. Increase in chromosomal aberrations was dose dependent manner. Pollen mother cells of Sesbania cannabina exhibited anincreased incidence of chromosomal bridges, unorientation, laggards and precocious movement etc. at each dose of treatment.Anaphasic and telophasic bridges were major abnormalities and found to be highest at 3 hr dose of treatment. Anaphasic bridgeswere more prominent than telophasic bridges and percentages of different types of bridges at anaphase and telophase were alsostudied and scored.