To make a comprehensive assessment on monosodium glutamate wastewater pollution, a pollution exposure experiment was carried out on the seed germination and root elongation of wheat, Chinese cabbage and tomato by using the wastewater discharged from different processing phases of monosodium glutamate production. The results showed that there were significantly positive linear relationships between the inhibition rates of wheat seed germination and root elongation and the COD(Cr) of mother liquor scraps. The toxicity of monosodium glutamate wastewater to the test crops was in the order of tomato > Chinese cabbage > wheat, indicating that tomato was most sensitive to the wastewater, and could be considered as an ideal toxic bioindicator. The half-effect concentration (IC50) based on the seed germination and root elongation of test crops exposed to the wastewater discharged from various processing phases of monosodium glutamate production was 22.0 to approximately 32432 mg x L(-1) and 17.3 to approximately 3320 mg x L(-1), respectively.