Method for preparing super absorbent polymer

A method for preparing a super absorbent polymer comprising:

• conducting crosslinking polymerization of water soluble ethylenically unsaturated monomers having acid groups at least a part of which are neutralized with an internal crosslinking agent, in the presence of an azo-based polymerization initiator and diethylenetriamine pentaacetic acid, to obtain a hydrogel polymer;
• and
• drying, grinding and classifying the hydrogel polymer to form base resin powder,
• wherein the azo-based polymerization initiator and the diethylenetriamine pentaacetic acid are included at a weight ratio of 1:2 to 1:10, wherein the base resin powder has a centrifuge retention capacity (CRC) measured according to EDENA method WSP 241.2, of 45.0 g/g or more and wherein gel strength measured using tension and compression tester is 0.30 N or more, said gel strength being measured by dipping 2.5 g of the base resin powder in 50 g of a saline solution of ascorbic acid and swelling the base resin powder in a 40° C. oven for 24 hours, and then, measuring the swollen base resin powder.