Ecotoxicological indexes of wheat, Chinese cabbage and rice exposed to reactive X-3B red dye were studied using the experimental method of crop seed exposure. The results showed that reactions of the three crops to reactive X-3B red dye were different from each other. Based on the inhibition of seed gemination, the half effect concentration(IC50) of wheat, Chinese cabbage and rice was 8965, 7010 and 7514 mg.L-1. Based on the inhibition of root elongation, the IC50 of wheat, Chinese cabbage and rice was 6534, 5882 and 4570 mg.L-1. When seedlings were cultured for seven days after the gemination of seeds and the remaining seeds or husks were discarded, fresh and dry growing biomass of the three crops exposed to the dye was both decreased with the increasing the concentration of reactive X-3B red dye. However, the decrease rate of fresh biomass was higher than that of dry biomass. Biomass index of wheat was most sensitive to reactive X-3B red dye, followed by rice, and Chinese cabbage was most inertia when the crops were exposed to reactive X-3B red dye with the high concentration of 4500 and 5000 mg.L-1. As far as the tolerance of wheat, Chinese cabbage and rice to reactive X-3B red dye was concerned, wheat had the strongest tolerance, on the contrary rice had the wakestone.