A catalyst composition for olefin polymerization, comprising: a transition metal compound represented by the following formula 1; and a transition metal compound represented by the following formula 2: wherein M as bonded to Q 1 and Q 2 is a Group 4 transition metal; Q 1 and Q 2 are independently a halogen, C 1 -C 20 alkyl, C 2 -C 20 alkenyl, C 2 -C 20 alkynyl, C 6 -C 20 aryl, C 1 -C 20 alkyl C 6 -C 20 aryl, C 6 -C 20 aryl C 1 -C 20 alkyl, C 1 -C 20 alkylamido, or C 6 -C 20 arylamido; R 1, R 2, R 3, R 4, R 5, R 6, R 7, R 8, R 9, and R 10 are independently hydrogen; C 1 -C 20 alkyl with or without an acetal, ketal, or ether group; C 2 -C 20 alkenyl with or without an acetal, ketal, or ether group; C 1 -C 20 alkyl C 6 -C 20 aryl with or without an acetal, ketal, or ether group; C 6 -C 20 aryl C 1 -C 20 alkyl with or without an acetal, ketal, or ether group; or C 1 -C 20 silyl with or without an acetal, ketal, or ether group,; and R 11, R 12, and R 13 are independently hydrogen; C 1 -C 20 alkyl with or without an acetal, ketal, or ether group; C 2 -C 20 alkenyl with or without an acetal, ketal, or ether group; C 1 -C 20 alkyl C 6 -C 20 aryl with or without an acetal, ketal, or ether group; C 6 -C 20 aryl C 1 -C 20 alkyl with or without an acetal, ketal, or ether group; C 1 -C 20 silyl with or without an acetal, ketal, or ether group; C 1 -C 20 alkoxy; or C 6 -C 20 aryloxy, wherein M as bonded to X is any one selected from the elements in Groups 3 to 10 of the periodic table; X is C 1 -C 20 alkyl, C 1 -C 20 alkylsilyl, C 1 -C 20 silylalkyl, C 3 -C 20 cycloalkyl, C 6 -C 20 aryl, C 6 -C 20 aryl C 1 -C 20 alkyl, C 1 -C 20 alkyl C 6 -C 20 aryl, C 6 -C 20 arylsilyl, C 6 -C 20 silylaryl, C 1 -C 20 alkoxy, C 1 -C 20 alkylsiloxy, C 6 -C 20 aryloxy, halogen, or amine; n is an integer from 1 to 5; Cp 1 and Cp 2 are independently a ligand with a cyclopentadienyl backbone; B is dimethylsilylene, diethylsilylene, diphenylsilylene, or ethylene; and q is an integer from 0 to 4. a transition metal compound represented by the following formula 1; and a transition metal compound represented by the following formula 2: wherein M as bonded to Q 1 and Q 2 is a Group 4 transition metal; Q 1 and Q 2 are independently a halogen, C 1 -C 20 alkyl, C 2 -C 20 alkenyl, C 2 -C 20 alkynyl, C 6 -C 20 aryl, C 1 -C 20 alkyl C 6 -C 20 aryl, C 6 -C 20 aryl C 1 -C 20 alkyl, C 1 -C 20 alkylamido, or C 6 -C 20 arylamido; R 1, R 2, R 3, R 4, R 5, R 6, R 7, R 8, R 9, and R 10 are independently hydrogen; C 1 -C 20 alkyl with or without an acetal, ketal, or ether group; C 2 -C 20 alkenyl with or without an acetal, ketal, or ether group; C 1 -C 20 alkyl C 6 -C 20 aryl with or without an acetal, ketal, or ether group; C 6 -C 20 aryl C 1 -C 20 alkyl with or without an acetal, ketal, or ether group; or C 1 -C 20 silyl with or without an acetal, ketal, or ether group,; and R 11, R 12, and R 13 are independently hydrogen; C 1 -C 20 alkyl with or without an acetal, ketal, or ether group; C 2 -C 20 alkenyl with or without an acetal, ketal, or ether group; C 1 -C 20 alkyl C 6 -C 20 aryl with or without an acetal, ketal, or ether group; C 6 -C 20 aryl C 1 -C 20 alkyl with or without an acetal, ketal, or ether group; C 1 -C 20 silyl with or without an acetal, ketal, or ether group; C 1 -C 20 alkoxy; or C 6 -C 20 aryloxy, wherein M as bonded to X is any one selected from the elements in Groups 3 to 10 of the periodic table; X is C 1 -C 20 alkyl, C 1 -C 20 alkylsilyl, C 1 -C 20 silylalkyl, C 3 -C 20 cycloalkyl, C 6 -C 20 aryl, C 6 -C 20 aryl C 1 -C 20 alkyl, C 1 -C 20 alkyl C 6 -C 20 aryl, C 6 -C 20 arylsilyl, C 6 -C 20 silylaryl, C 1 -C 20 alkoxy, C 1 -C 20 alkylsiloxy, C 6 -C 20 aryloxy, halogen, or amine; n is an integer from 1 to 5; Cp 1 and Cp 2 are independently a ligand with a cyclopentadienyl backbone; B is dimethylsilylene, diethylsilylene, diphenylsilylene, or ethylene; and q is an integer from 0 to 4.