Fotoditazin, photosensitizer of second generation, is used in photodynamic therapy of tumors. In order to improve selectivity of drug accumulation in tumor tissue and improve the stability of the drug during storage, « Lyophilized liposomal fotoditazin for solution for injection 1,5 mg», a new liposomal drug form of fotoditazin, has been worked out in N. N. Blokhin Russian Cancer Research Center. This paper presents methods for identification of egg phosphatidylcholine, fotoditazin and methods of fotoditazin assay in the new lyophilized liposomal drug.