A catalyst composition comprising: (a) a bidentate ligand represented by formula 1 below; and (b) a transition metal catalyst represented by formula 2 below: wherein, R 1 and R 2 are each unsubstituted alkyl group of 1-20 carbon atoms, unsubstituted alkoxy group of 1-20 carbon atoms, unsubstituted cycloalkane or cycloalkene of 5-20 carbon atoms, unsubstituted aryl group of 6-36 carbon atoms, unsubstituted heteroalkyl group of 1-20 carbon atoms, or unsubstituted hetero ring group of 4-36 carbon atoms; Ar 1 -Ar 2 is a bisaryl compound; and R 3 is an alkyl group of 1-20 carbon atoms, an aryl group of 6-20 carbon atoms, a triarylsilyl group, a trialkylsilyl group, a carboalkoxy group represented by -CO 2 R where R is an alkyl group of 1-20 carbon atoms or an aryl group of 6-20 carbon atoms, a carboaryloxy group, an aryloxy group, an alkoxy group, an alkylcarbonyl group, an arylcarbonyl group, an amide, a halogen, or a nitrile group, and M(L 1),(L 2) m (L 3) n wherein, M is cobalt (Co), rhodium (Rh), or iridium (Ir); L 1, L 2 and L 3 are each hydrogen, CO, acetylacetonato, norbornene, chlorine, or triphenylphosphine; and l, m, and n are each an integer of 0 to 5, and the sum of l, m and n is not zero. (a) a bidentate ligand represented by formula 1 below; and (b) a transition metal catalyst represented by formula 2 below: wherein, R 1 and R 2 are each unsubstituted alkyl group of 1-20 carbon atoms, unsubstituted alkoxy group of 1-20 carbon atoms, unsubstituted cycloalkane or cycloalkene of 5-20 carbon atoms, unsubstituted aryl group of 6-36 carbon atoms, unsubstituted heteroalkyl group of 1-20 carbon atoms, or unsubstituted hetero ring group of 4-36 carbon atoms; Ar 1 -Ar 2 is a bisaryl compound; and R 3 is an alkyl group of 1-20 carbon atoms, an aryl group of 6-20 carbon atoms, a triarylsilyl group, a trialkylsilyl group, a carboalkoxy group represented by -CO 2 R where R is an alkyl group of 1-20 carbon atoms or an aryl group of 6-20 carbon atoms, a carboaryloxy group, an aryloxy group, an alkoxy group, an alkylcarbonyl group, an arylcarbonyl group, an amide, a halogen, or a nitrile group, and M(L 1),(L 2) m (L 3) n wherein, M is cobalt (Co), rhodium (Rh), or iridium (Ir); L 1, L 2 and L 3 are each hydrogen, CO, acetylacetonato, norbornene, chlorine, or triphenylphosphine; and l, m, and n are each an integer of 0 to 5, and the sum of l, m and n is not zero. R 1 and R 2 are each unsubstituted alkyl group of 1-20 carbon atoms, unsubstituted alkoxy group of 1-20 carbon atoms, unsubstituted cycloalkane or cycloalkene of 5-20 carbon atoms, unsubstituted aryl group of 6-36 carbon atoms, unsubstituted heteroalkyl group of 1-20 carbon atoms, or unsubstituted hetero ring group of 4-36 carbon atoms; Ar 1 -Ar 2 is a bisaryl compound; and R 3 is an alkyl group of 1-20 carbon atoms, an aryl group of 6-20 carbon atoms, a triarylsilyl group, a trialkylsilyl group, a carboalkoxy group represented by -CO 2 R where R is an alkyl group of 1-20 carbon atoms or an aryl group of 6-20 carbon atoms, a carboaryloxy group, an aryloxy group, an alkoxy group, an alkylcarbonyl group, an arylcarbonyl group, an amide, a halogen, or a nitrile group, and M(L 1),(L 2) m (L 3) n wherein, M is cobalt (Co), rhodium (Rh), or iridium (Ir); L 1, L 2 and L 3 are each hydrogen, CO, acetylacetonato, norbornene, chlorine, or triphenylphosphine; and l, m, and n are each an integer of 0 to 5, and the sum of l, m and n is not zero.