Abstarct: The use of fish industry wastes, as a fertilizer, has been common in order to improve different soils and agricultural production. In this research, a greenhouse experiment was performed as factorial baxsed on the complete randomized block desing with three replications, in order to study the effect of fish wastes on some soil properties and Cowpea and also compare their performance with biological and chemical fertilizers. The fish flour factor was in three levels including: without usage (F0), half of local custom (F1 500 kg per hectare) and local custom (F2 1000 kg per hectare) and chemical fertilizer including: NPK (that respectively were used in the soil in the forms of urea, triple superphosphate and solo potassium fertilizers) in three levels including: without usage (N0P0K0), half of local custom (N1P1K1) (potassium 35 kg per hectare, phosphorus 40 kg per hectare, nitrogen 25 kg per hectare) and local custom (N2P2K2) (potassium 70 kg per hectare, phosphorus 80 kg per hectare, nitrogen 50 kg per hectare) and pseudomonas in two levels including: without usage (B0) and usage (B1) were used. The results showed that the application of fish fertilizer alone, was caused to increase the weight of the pod, chlorophyll, the protein of grain. The amount of phosphorous and potassium of grain. But the largest increase was in the treatment with the application of fish and chemical fertilizer simultaneously. The highest and lowest amounts of protein of grain, respectively, were in the combined treatments with chemical fertilizers, fish wastes and pseudomonas into 34.12 % and in control into 11.87 %, while using of chemical fertilizer alone, did not have any significant effect on increasing of the amount of protein in grain. The results also showed that soil salinity, soil pH, the percent of soil organic matter and soil phosphorus were influenced by the application of fish fertilizer significantly, while the highest rate of salinity and the percent of soil organic matter was seen in 1000 kg fish wastes per hectare level. But using more than 500 kg fish wastes per hectare caused to decrease pH and and soil phosphorus. In general, the results of this research showed that the application of fish wastes has a significant role in improving the yield and Cowpea yield components and also can be considered as a suitable supplement for chemical fertilizers