Polyester polymerization catalyst, polyester produced by using the same, and a process for producing polyester

The present invention provides processes for producing polyester. In one of the embodiments, the invention provides a process for producing polyester, comprising adding a catalyst in a polycondensation reaction, esterification reaction or transesterification reaction between components comprising at least a polyfunctional alcohol and at least a polyfunctional carboxylic acid or ester-forming derivative of a polyfunctional carboxylic acid to produce the polyester; and obtaining the polyester, wherein the polymerization catalyst comprises an aluminum substance and a phosphorus compound, wherein the aluminum substance is selected from the group consisting of aluminum hydroxide and aluminum alkoxides, and wherein the phosphorus compound has an aromatic ring structure.