Abstract: Effect of atrazine was determined on the absorption and accumulation of phosphorous (P32 ) in bean plants and results have been explained in relation to other physiological processes. Atrazine seemed to be highly toxic to the seedlings at all concentrations used. The injury caused by the herbicide increased with its concentration. It was found to decrease the contents of chlorophyll a, chlorophyll b and carbohydrates, which reflects its effectiveness as a photosynthetic inhibitor. Potassium and protein contents were decreased significantly at 10 to 100 ppm atrazine. The uptake of phosphorus was also recorded and it declined with time. The accumulation of P32 was inhibited at 10 to100 ppm concentrations of atrazine. Some growth stimulating effects were also observed at 5 ppm level.