Aim. The optimization of conditions for bacterial expression of recombinant protein AIMP1/p43 has been carried out in order to increase the yield of stable protein in solution. Methods. Protein expression in bacterial expression system, metal-chelating affinity chromatography, gel-electrophoresis. Results. The influence of expression inductor IPTG concentration on final yield of target protein has been studied. The optimal time and temperature of cultivation of bacterial culture with inductor has been investigated. Optimal culturing conditions for Escherichia coli BL21(DE3)RIL cultivation have been proposed to achieve a high expression level of soluble recombinant protein. Conclusions. It has been established that the yield of soluble recombinant AIMP1/р43protein increased significantly with the decrease of IPTG concentration to 0,5 мМ, decrease of temperature to 25оС and increase of cultivation time to 8 h. This gives one the possibility of preparing the protein AIMP1/р43 in enough amount for its further structural studies and use as a new molecular biotechnological product.