Frame structure on a slope is a common kind of structure in a mountainous area. It can diminish the impact on environment, by avoiding to dug or fill the slope, using an opening platform, supported by beams and columns. Because the frame structure on a slope connects with the ground on different elevation level, it is evidently different from general frame structure in seismic design. Four sets of frame structure example on a slope sample are designed, with three opening floors connected with the ground on different elevation level, and three, six, nine, twelve upper floors correspondingly. The seismic responses characteristics of frames on a slope are studied in the paper from period, lateral deformation, seismic shear and so on, based on the analysis of the characteristics of frame structure on a slope. The main conclusions are as follows: the slope can enhance structural lateral stiffness to a certain extent; the opening floors connected with the ground on different elevation level, are not necessarily frail stories; the distribution of seismic force is uneven between the columns in the same floors which connect with the ground on different elevation level, and fixed columns undertake more than others, making them more fragile; the torsional effect is noticeable in the frame structure on a slope.