A pot experiment was conducted to study effects of two kinds of herbicides, varying in dosage, on bio-characteristics of paddy soil and nutrients absorption and accumulation of succeeding crops. Results show that the application of either bensulfuron-methyl•butachlor or quinclorac in paddy soil decreased the dry matter weight of Chinese milk vetch, and the higher the application rate, the less the dry matter accumulated. Low doses of bensulfuron-methyl•butachlor significantly decreased N accumulation in Chinese milk vetch, while low doses of quinclorac decreased not only N, also K accumulation in the plant. And high doses of either of the two herbicides decreased N, P and K accumulation in the plant. The application of either bensulfuron-methyl•butachlor or quinclorac, regardless of dosage, decreased the availability of soil N and K. Low doses of quinclorac did not affect much available P content in the soil, while high doses of the herbicide did significantly decrease the availability of soil P. Low doses of bensulfuron-methyl•butachlor did not have much influence on the activities of catalase, sucrase and urease in the soil, while low doses of quinclorac inhibited markedly the activities of catalase. High doses of either of the herbicides did not affect much the activity of sucrase, but did inhibit those of catalase and urease. Furthermore, the application of bensulfuron-methyl•butachlor, either high or low in dosage, increased the amount of bacteria, and while that of quinclorac acted just reversely. The application of either of the herbicides at either high or low rate, decreased the amount of actinomyce, but did not cause much change in that. It is, therefore, quite clear that, the application of quinclorac in paddy field is more harmful to the paddy soil environment and the growth of Chinese milk vetch than bensulfuron-methyl•butachlor.