Provided is a method for producing carboxyalkyl starch. According to the present invention, a fluid is absorbed by personal hygiene items, and retention capacity of the carboxyalkyl starch is improved, thereby reducing re-discharge of the fluid. The method for producing the carboxyalkyl starch comprises the following steps: primarily cross-linking the starch after carrying out a reaction between the starch and a cross-linking agent； carrying out a carboxyalkyl substitution by treating the same with a carboxyalkylation agent； and reacting the same with a cross-linking agent so as to cross-link the same.위생용품으로 유체를 흡수하고 보유능을 향상시켜 유체의 재방출을 줄여줄 수 있는 카르복시알킬 전분 제조방법이 제공된다. 상기 카르복시알킬 전분 제조방법은 전분에 가교제를 반응시켜 선가교처리하는 단계, 이에 카르복시알킬화제를 처리하여 카르복시알킬 치환하는 단계 및 이에 가교제를 반응시켜 가교처리하는 단계를 포함한다.
