(1.Plant Protection Institute，Heilongjiang Academy of Agricultural Sciences，Harbin，Heilongjiang 150086；2.Information Center，Heilongjiang Academy of Agricultural Sciences，Harbin，Heilongjiang 150086)
33% pendimethalin EC was used as test materials,its contribution control effects to weed and dosage were studied,to provide scientific basis for pharmaceutical application.The results showed that 33% pendimethalin EC was safe in cabbage fields after transplanting；it could well control gramineae grassy weeds and broad-leaved weeds.The active ingredients of 33% pendimethalin EC were 618.8—742.5 g/hm2 ，weed control effect to gramineae grassy weeds within the recommended dose was 80.5%—84.7% by plant number，and 88.1%—91.6% by fresh weight.The broad leaf weeds control effect of 89.6%—94.3% by plant number，fresh weight control effect of 93.5%—96.8%.