Some potato resistant starches (AH-HMT RS3) were made by using acid hydrolysis combined with heat-moisture treatment (AH-HMT), and the effects of different types and concentration of organic acids and the starch slurry concentration on the formation of slowly digestive starch (SDS) and resistant starch (RS) in potato RS3 were investigated. The results demonstrated that the starch slurry concentrations had no effect on the formation of SDS and RS when the potato starches were modified by no acid combined with heat-moisture treatment (HMT). Compared with no acid-HMT, the RS contents in potato AH-HMT RS3 made by AH-HMT increased 21.89%～45.09%, non-influenced by the starch slurry concentration. As to the improvement of RS formation, high acid concentration was better that the lower one. The increased levels of RS from high to low were ordered as citric acid, acetic acid, succinic acid and latic acid. With the increase of RS content, the potato AH-HMT RS3 had stronger effect on the proliferations of bifidobacteria and lactobacilli and could promote more short chain fatty acids (SCFAs), especially butyric acid formation. Therefore, potato AH-HMT RS3 had the developmental potential of a new probotic.