Since the 1980s, long term field experiments have been carried on to study effect of straw application on soil fertility in Changshu (Jiangsu Province) and Red Soil Institute (Jiangxi Province), separately. Results showed that total nitrogen, total phosphorus, readily available phosphorus and readily available potassium in the treatment of chemical fertilizer plus straw were significantly increased compared with CK (no fertilization) in both Wu Shan soil and red paddy soil and with the treatment of chemical fertilizer alone in red paddy soil (P<0.05). Likewise, the content of organic matter of the chemical fertilizer plus straw treatment in the two soils was higher than that of the treatment of chemical fertilizer. Moreover, fractionation analysis of humus also revealed that humic acid carbon, and HAC/FAC ratio was significantly increased, suggesting that the quality of organic matter in the soils was significantly improved. In conclusion, soil fertility could be improved through application of chemical fertilizer plus straw in Wu Shan soil and red paddy soil.