Abstract: An experiment of long time was carried out for 20 years to study the influence of applying organic fertilizers or ration application of organic and chemical fertilizers on soil fertility and rice yield .The result were concluded as followings: (1) The total N content of soil was higher than chemical fertilizers, the effective N increased15.9mg/kg,when the organic fertilizers applied. (2) It was foundation of improving the soil PK nutrient to applying the PK fertilizer . The effective P, K content of soil increased 18.8, 27mg/kg in average to apply fertilizer. (3) Applying the organic fertilizer could improve the soil physical property, rational application could not obviously change pH . The organic fertilizer made soil capacity drop by 12.6%, the capacity of field water rise by 19.7%. (4) Rational application of organic and chemical fertilizers in succession, can stable increase yield in lastly. The total rice yield (the average yield of two seasons of 19 years) in the treatment of applying N P K Mg was 5556.8kg/hm2, which was 704.3kg/hm2 (14.5%.) higher than the treatment of only applying chemical fertilizer NPK.