Abstract: In order to improve the starch indigestibility, the preparation of digestion resistance corn starch citrate was investigated.On the basis of the results of single factor experiment, citric acid concentration, pH, urea concentration, and phosphorylation temperature were analysed in central composite design to optimize the starch indigestibility.Results showed that the optimum preparation technology required 11.3% concentration in citric acid, a pH of 2.8, urea concentration 4.7%, and phosphorylation temperature 138℃.Under these conditions, the verified value of the starch digestion resistance produced by the resulting corn starch citrate was yield of 94.13% ± 0.05%.