Fish wastes such as skin, scales, bones and fins are major by-products in the fishery and aquaculture industries have received significant attention in recent years as an alternative source of collagen. Acid-soluble collagen (ASC) was extracted from the skin of catfish (Clarias lazera).  It was characterized in terms of chemical composition (moisture, protein, fat and ash content), Thermal denaturation temperatures (Td), solubility, SDS-PAGE and amino acid analysis.  The results indicated that the yield of ASC was 5.2% (wet weight basis). The chemical compositions of raw skin were 56.62%, 32.50%, 6.67 and 2.93% while the chemical compositions of ASC 14.03 %, 83%, 1.5% and 1.44% for moisture, protein, fat, and ash, respectively.  The distinct absorption of collagen was obtained near 230 nm .The Maximum solubility was (3 mg/ml) in 0.5 M acetic acid at pH 2.5. The denaturation temperature (Td) of ASC was 27 °C and Hunter color L, a, and b values were 76.90, - 3.36 and 13.98 respectively. In conclusion, the characteristics of the isolated ASC indicate that catfish skin had good yield of collagen and it could be served as alternative source of collagen for some applications.