Abstract: The fixed position experiments were carried out on rice and wheat with the application of organic plus chemical fertilizers for 12 years. The results showed that among three treatments containing chemical fertilizer，the effective panicles of wheat and single-cropping late rice increased 869，000 kg/hm2 in two seasons with the treatment of manure plus chemical fertilizer in comparison with the return of rice stalk plus chemical fertilizer，meanwhile，the effective panicles of wheat and single-cropping late rice increased 116，000 kg/hm2 in two seasons with the treatment of the return of rice stalk plus chemical fertilizer in comparison with the single application of chemical fertilizer. In addition，the average crop yield per year of wheat and single-cropping late rice increased 367.5 kg/hm2 in two seasons with the treatment of manure plus chemical fertilizer in comparison with the return of rice stalk plus chemical fertilizer，whose increasing rate was 3.4%. Compared with the single application of chemical fertilizer，the increasing rate was 5.8% when treated with the return of rice stalk plus chemical fertilizer. Among three treatments without chemical fertilizer，the effective panicles of wheat and single-cropping late rice increased 333，000 kg/hm2 in two seasons with the treatment of manure plus chemical fertilizer in comparison with the return of rice stalk plus chemical fertilizer，meanwhile，the effective panicles of wheat and single-cropping late rice increased 199，500 kg/hm2 in two seasons with the treatment of the return of rice stalk plus chemical fertilizer in comparison with no fertilizer （the control）. The average crop yield per year of wheat and single-cropping late rice increased 277.5 kg/hm2 in two seasons with the treatment of manure plus chemical fertilizer in comparison with the return of rice stalk plus chemical fertilizer，whose increasing rate was 7.4%. Compared with the control，the increasing rate was 15.8% when treated with the return of rice stalk plus chemical fertilizer. The contents of soil organic matter，total nitrogen，total phosphorus，available nitrogen and available phosphorus increased with application of the manure plus chemical fertilizer and the return of rice stalk plus chemical fertilizer，among which，the increase amplitude was the biggest with the treatment of manure fertilizer，the treatment of straw returning took second place and the increase amplitude with the treatment of inorganic fertilizer was smaller. The variation degree of total potassium and available potassium was different. In conclusion，the application of manure plus chemical fertilizer could effectively increase the crop yield and improve the soil characters.

Key words: organic fertilizer, chemical fertilizer, organic plus chemical fertilizer application, crop yield, soil nutrients