Abstract: Highly active catalyst for the polymerization of olefins and method for the preparation of the same.The catalyst for the polymerization of olefins, consisting essentially of-magnesium, titanium, halogen and at least one electron donor, wherein the electron donor is selected from the group consisting of aliphatic unsaturated esters, aliphatic saturated esters, aromatic esters and the mixture thereof, which all contain at least one hydroxy group.The catalyst is prepared by directly reacting a magnesium compound of liquid phase having no reducing power with a titanium compound of liquid phase in the presence with at least one electron donor.Superior in activity as well as production yield in polymerizing olefins, the catalyst is capable of not only providing the polymer with high stereoregularity but also improving the bulk density of the polymer, especially polyethylene.