one or more of a first transition metal compound represented by Chemical Formula 1;

one or more of a second transition metal compound represented by Chemical Formula 2; and

a support on which the first and second transition metal compounds are supported:

in Chemical Formula 1,

M₁ is a transition metal of Group 4;

Cp¹ and Cp² are the same as or different from each other, and each independently, any one selected from the group consisting of cyclopentadienyl, indenyl, 4,5,6,7-tetrahydro-1-indenyl, and fluorenyl radicals, which are unsubstituted or substituted with C_1-20 hydrocarbon;

R₁₁ and R₁₂ are the same as or different from each other, and each independently, hydrogen, C_1-20 alkyl, C_1-20 alkoxy, C_2-20 alkoxyalkyl, C_6-20 aryl, C_6-20 aryloxy, C_2-20 alkenyl, C_7-40 alkylaryl, C_7-40 arylalkyl, C_8-40 arylalkenyl, C_2-20 alkynyl, or C_2-20 heteroaryl comprising one or more heteroatoms of N, O, or S;

Z₁ is halogen, C_1-20 alkyl, C_2-20 alkenyl, C_7-40 alkylaryl, C_7-40 arylalkyl, C_6-20 aryl, an amino group, C_2-20 alkylalkoxy, or C_7-40 arylalkoxy; and

m is 1 or 0;

in Chemical Formula 2,

A is carbon or silicon,

M₂ is a transition metal of Group 4,

R₂₁ is C_6-20 aryl substituted with C_1-20 alkyl,

R₂₂ is C_3-20 branched alkyl,

R₂₃ to R₂₅ are each independently C_1-20 alkyl,

Z₂₁ and Z₂₂ are each independently halogen or C_1-10 alkyl, and

n is an integer of 1 to 10.