Abstract: Nimodipine is a selective calcium channel antagonist of cerebral vessels smooth muscle and also has polymorphs. It hasn't been reported that different crystal forms influence the metabolism process in huge animals like rhesus monkeys in vivo. This article may provide reference in the control of the quality of nimodipine and quality consistency evaluation. The powder X-ray diffraction (PXRD) method was used to identify different crystal forms and the dissolution test in vitro was used to detect the dissolution. The LC-MS method of assay nimodipine in rhesus monkey plasm was established to determine pharmacokinetics characters of different tablets from different crystal forms in rhesus monkey in vivo. As a result, the tablets inherit difference crystal forms and the dissolution of reference tablets is 1.3% higher than crystal tablets. However, the maximal blood concentration (C_max) of crystal tablet was 37.3% higher than reference tablet and AUC of crystal tablet was 29.8% higher than reference tablet. After administrated 2.5 mg·kg^-1 orally, calculated pharmacokinetics characters were observed as following:C_max was 381.4 ±327.3 and 178.0 ±214.8 μg·L^-1; AUC_0-t was 853.1 ±500.7 and 646.5 ±430.3 μg·L^-1·h respectively. The serum concentration result of different nimodipine tablets in rhesus monkeys in vivo suggests that polymorphs has a significantly distinction, which points out that controlling the crystal forms of nimodipine is essential to ensure the therapeutic efficacy. It is essential to execute quality consistency evaluation.