Abstract: In order to rationally utilize organic fertilizers, the mineralization of carbon and nitrogen in organic manures, Astragalus sinicus L., rapeseed cake and hen manure, in cigar wrapper tobacco fields was studied.The results showed that:1) organic carbon in Astragalus sinicus L.had an obvious mineralizing stage during the first 6 weeks after being embedded in soil, while in stockpiled rapeseed cake and hen manure it was in a relatively higher mineralizing status through whole growing season;2) mineralizing rate of nitrogen in Astragalus sinicus L.was higher than the others, and 93% of nitrogen in whole growing season was released in 8 weeks after being embedded in soil, well harmonized with the requirement for the growth of tobacco plants.