In this study, we assessed the effects of heat treatment on the in vitro hydrolysis indices of commercial Saengshik. Thermal treatment on grain flour and commercial Saengshik increased soluble dietary finer(SDF) and insoluble fiber(IDF), while total dietary fiber(TDF) content remained nearly constant regardless of thermal treatment. Among the samples, COS(Commercial Ohaeng Saengshik) showed the highest TDF and IDF content in raw and heated samples. Additionally, the resistant starch(RS) contents in unheated samples were shown to be high. After heating, the RS levels of all the samples were reduced significantly, by over 12%. The degree of gelatinization in the unheated samples was lower than that of the heated samples, whereas the degree of retrogradation in the unheated samples was higher than that of the heated samples. The hydrolysis indices(HI) of the unheated samples were relatively low, whereas the heated group evidenced high levels. The HI must be affected by content of RS and IDF in samples.