Using tomato as experimental materials,an experiment for combined application of straw and chemical fertilizer was conducted by randomized block design to study the effects of straw on soil physical and chemical characteristics in vegetable land.The result showed that after the combined application of straw and chemical fertilizer soil bulk density declined by 0.7 %~10.1 %,soil porosity increased by 0.14 %~9.87 %.The content of soil organic matter as well as available N,P,K also increased.The soil physical and chemical characteristics were improved obviously after 0.5a of combined application of straw and chemical fertilizer in vegetable land.The soil bulk density of T2,T3 and T4 was 4.65 %,10.10 %,8.91 % lower than CK,respectively.The soil porosity of T2,T3 and T4 was 2.30 %,4.98 %,4.42 % higher than CK,respectively.Compared with that of the control,organic matter increased by 0.037 %,0.082 %,0.064 %,alkaline hydrolysis N increased by 1.7 mg/kg,6.8 mg/kg,5.4 mg/kg,available P increased by 2.45 mg/kg,4.22 mg/kg,3.18 mg/kg,available K increased by 5.4 mg/kg,14.2 mg/kg,12.3 mg/kg,respectively.Among those treatments,all determined indexes of T3 were significantly or extremely significantly better than CK.The experiment proved that the combined application of straw and chemical fertilizer was a good way of maintaining and improving soil fertility in vegetable land.Meanwhile,the best effects came when the application quantity of straw was 300kg per 666.7 m².