This study was carried out to study the effect of adding different levels of the microalgae Spirulina spp. in fish laboratory of Animal Sciences Department, College of Agricultural Sciences of Sulaimani University, Sulaimani, Iraq. A total of 72 common carp fingerling weight 45±2 gm used to detect the effect of three different levels of the algae Spirulina spp. The control treatment T1 with 0%., T2 with 3 gm /kg diet and T3 with 5 gm Spirulina /kg diet. Each treatment in three replicates in which six fingerlings common carp were stocked in each aquarium. Results indicated no significant differences at PSpirulina) in T3 was higher significantly at PSpirulina was higher significantly at PSpirulina to common carp diets in different levels leads to significant differences in differential WBC counts, T3 with 5 gm Spirulina /kg diet was higher in WBC counts. Lymphocytes were higher in each of control and T3. Monocytes were higher in control, granulocytes in T2 with 3 gm Spirulina /kg diet. Adding of Spirulina affected significantly in cholesterol as compared to the control. Triglyceride was higher in control and T2. T3 with 5 gm Spirulina /kg diet leads to higher and lower significantly in HDL and LDL respectively. T1 and T3 were higher significantly in spleenosomatic index. Inclusion of S. platensis in fish diet as a feed additive or as a partial replacer of the expensive fishmeal imposes significant promotions in fish growth, coloration, reproduction and flesh quality.