Abstract: OBJECTIVE To investigate the influence of nisoldipine on distribution of isosorbide-5-mononitrate in mice tissue. METHODS Healthy male mice were divided into isosorbide-5-mononitrate group and isosorbide-5-mononitrate combined with nisoldipine group. The content of isosorbide-5-mononitrate in tissues was detected by HPLC. RESULTS Tissue concentrations of isosorbide-5-mononitrate at 0.083 h post-dosing were in the order of small intestine＞stomach＞heart＞liver＞kidney, and stomach＞small intestine＞kidney＞heart＞liver at 0.5 h post-dosing. The highest concentration time of isosorbide-5- mononitrate in stomach was 0.083 h after combined administration; the highest concentration time of isosorbide-5-mononitrate in stomach was 0.5 h after single administration. There were significant differences in highest concentrations of isosorbide-5- mononitrate in stomach of 2 groups(P<0.05). CONCLUSION Nisoldipine has some influence on distribution of isosorbide-5- mononitrate in mice tissue.