A conversion coating composition comprising 0.01 wt % to 0.2 wt % of phosphorous (P); 0.01 wt % to 0.2 wt % of magnesium (Mg); 0.005 wt % to 0.15 wt % of zirconium (Zr); 0.005 wt % to 0.15 wt % of titanium (Ti); 0.005 wt % to 0.15 wt % of vanadium (V); 0.05 wt % to 1 wt % of phenol resin; the balance of water and other unavoidable impurities is provided. A surface treated steel sheet comprising a base steel sheet; a zinc or zinc alloy plated layer formed on the base steel sheet; a blackening layer formed on the zinc or zinc alloy plated layer; and an organic and inorganic complex conversion coating layer formed on the blackening layer, wherein the organic and inorganic complex conversion coating layer may satisfy the weight ratio of P:Mg:Zr:Ti:V=1:0.045 to 2:0.035 to 1.5:0.035 to 1.3:0.035 to 1.5 (based on the weight of P) is also provided. A method for manufacturing a steel sheet treated with the conversion coating composition is also provided.