Efficacy of photodynamic therapy with intraperitoneal introduction photosensitizer Amidoaminchlorine on rat sarcoma M1 model was studied. The aim of this study was to determine minimum effective dose of photosensitizer and parameters of laser radiation for achievement of tumor full regress. Dynamics of photosensitizer accumulation in tumor and healthy tissues was studied to definite the time of photodynamic therapy. Antitumor efficacy different doses of photosensitizer and various parameters of laser radiation were investigated. As a result, optimal term of photodynamic therapy, photosensitizer minimum effective dose and parameters of laser irradiation were established.