Thermally modified potato starch was prepared by dry heat treatment，mixing potato starch with xanthan, sodium alginate and sodium carboxymethyl cellulose (CMC), respectively. The effects of dry heat treatment on the physicochemical properties of the mixtures were researched. The results indicated that the gel hardness, gumminess, chewiness and thermal stability of potato starch-CMC and potato starch-xanthan significantly increased after dry heating. However, those of potato starch-sodium alginate had no significant difference between before and after dry heating. Fourier transform infrared spectra (FTIR) results exhibited that the peaks of all samples after dry heating shifted to a lower wavelengths, showed that hydrogen bonds between starch molecular chains were strengthened. The results indicated that the interaction between starch chain and ionic gums occurred during dry heat treatment.