The present invention relates to an organ toxicity diagnostic biomarker composition comprising exosome or a protein of same, an organ toxicity diagnostic composition comprising a formulation for detecting exosome or a protein of same, an organ toxicity diagnostic kit comprising the composition, a method for providing information for organ toxicity diagnosis using the composition, and a method for screening an organ toxicity therapeutic material comprising the composition. By using exosome according to the present invention, organ toxicity can be quickly diagnosed and, in particular, toxicity of a particular organ can be diagnosed by using an organ-specific exosome protein. Therefore, the present invention can be utilized for accurate and quick diagnosis or prognosis of organ toxicity due to various drugs.