Abstract: The compound hainanmycin sodium solution was prepared by using hainanmycin sodium, trimethoprim, emulsifier and proper solvent. The quality of the prepared solution was evaluated using the method recommended by national standard. Furthermore, the therapeutic efficacy of compound hainanmyein sodium solution on artificial infection of coccidian in chicken was investigated. The color of the prepared hainanmycin sodium solution was dark blue, and the content of hainanmycin sodium in the solution was 98.86% of the labeled amount. All of the crucial indexes investigated in stability test met standard requirements. The number of chickens with diarrhea and death chickens in the group administrated with compound hainanmycin sodium solution was fewest, and the effective cure rate was the highest （95%）, which was obviously higher than that of the two control groups. The quality of the prepared compound hainanmycin sodium solution was stable, and it showed obvious therapeutic efficacy on chicken coccidiosis.