The present invention provides a Ziegler-
Natta catalyst for
olefin polymerization, a method for producing polyolefins, and a
polyolefin resin. Specifically, the present invention provides a Ziegler-
Natta main catalyst for
olefin polymerization comprising a
titanium compound represented by formula 1, a
magnesium compound represented by formula 2, and an internal
electron donor; an organoaluminum compound represented by formula 7; and an external
electron donor represented by formula 3, wherein the internal
electron donor is a mixture of a first internal
electron donor selected from formulas 4 to 6 and a second internal
electron donor selected from formulas 4 to 6 and different from the first internal
electron donor, wherein in 10 moles of the mixture, the first internal electron donor and the second internal electron donor are present in a
molar ratio of 3:7 to 7:3. The present invention provides a Ziegler-
Natta catalyst for
olefin polymerization, a method for producing polyolefins using the same, and a
polyolefin resin produced using the same.