In order to determine the effect of air pollution on protein content of pollen, two species of Cassia viz. C. siamia L. and C. fistula L were studie from industrial area of Nagpur (MIDC, Hingna). Civil lines area was considered as control area. Pollen proteins were extracted, and analyzed by SDS PAGE method. Total protein content of pollen extracts was measured by method of Lowry et. al. (1951). Our investigations revealed noticeable differences in protein contents. According to observations more bands for protein were obtained for samples from control area as compared to samples from polluted area. Variations in protein contents were correlated with industrial pollution.