Abstract: To explore the effects of microbial fertilizer on growth, yield and soil nutrients of buckwheat under different nitrogen application. A field experiment was conducted with five treatments (A1 ~ A5) as follows: water the seed+90kgN/hm2, bacterial manure dress seeds and spraying+67.5kgN/hm2, bacterial manure dress seeds and spraying+45kgN/hm2, bacterial manure dress seeds and spraying+22.5kgN/hm2, bacterial manure dress seeds and spraying+0kgN/hm2. The physiological indexes and nutrient contents of buckwheat plants were measured. The results showed that: Treatment A3 had a highest yield as 158.4kg/mu, the increase extent was 14.45%; There was no significant difference on the yield and yield affecting factors between the treatments of biological fertilizer applicated and no biological fertilizer under different nitrogen application. The biological fertilizer seed treatment had obvious promotion and decomposition effect on the organic matter, the available phosphorus and the quick-acting potassium and the quick-acting nitrogen in the soil.