The Changshu tablet (CST), one kind of Chinese patent medicine with astringent to the intestine and relieving diarrhea, was made by the root of Rose odorata Sweet var. gigantean (Coll.et Hemsl.) Rehd.et Wils. Although CST has a long history of clinical application, but the research of its chemical composition is less. So the objective of this study was to investigate the main constituents and preliminarily research its effect of the contraction of isolated intestine in vitro. The contents of total polyphenols (126.23mg/g) and total triterpenoids (132.75mg/g) in CST were determined by ultraviolet spectrophotometry. Procyanidin B3, epigallo catechin, catechin, epicatechin, (-)-fisetinidol-(4α, 8)-(-)-catechin, (4α, 8)-(-)-fisetinidol-(-)-epicatechins and (+)-guibourtinidol-(4β, 8)-epicatechin were identified and determined by high performance liquid chromatography and their contents were distributed from 0.04mg/g to 1.46 mg/g. CST showed significant inhibitory effect against acetylcholine-induced contraction on the rat-isolated intestinal smooth muscle with a dose-dependent manner from 0.06 to 0.6mg/mL. The maxim inhibition rates of CST on duodenum, jejunum, ileum and colon were 65.70±3.47%, 79.74±1.27%, 58.90±1.87% and 45.75±2.21% respectively. These results indicated that CST has a spasmolytic role in gastrointestinal motility which was probably mediated through inhibition of muscarinic receptors. All these findings promote the improvement of the quality control standard of CST and provide pharmacological foundation for clinical application of CST in gastrointestinal tract.