The existing literature was reviewed to address the direct and indirect effects of chemical herbicides on the bio-communities in agroecosystems. Continual use of chemical herbicides may bring about the resistance of weeds to herbicides, accelerate the succession and decrease the biodiversity of the weed community. If abused, herbicides might change the biochemical composition of the crops, affect the nitrogen metabolism and the crop's resistance to pests and diseases, aggravate or alleviate plant diseases a...