Objective To assess the relationship between the BMI and the brain DAT, and the influence of BMI on the brain SPECT imaging with 99Tcm-TRODAT-1. Methods MRI and 99Tcm-TRODAT-1SPECT imaging were performed in 31 healthy volunteers(16 males and 15 females), and then the three-dimensional reconstruction of SPECT images were completed. Based on the MRI images, right striatum (RST) and the left striatum (LST) were drawn as ROI on the 4 most clearly consecutive transverse slices.The cerebellum (CB) was taken as the background reference area and the corresponding uptake ratios of ST/CB, LST/CB and RST/CB were calculated. The Pearson correlation tests for radio-uptake ratios (ST/CB, LST/CB, RST/CB), BMI and age were performed, Then multiple linear regression analysis using ST/CB as dependent variable and BMI and age as independent variables was performed. SPSS 15.0 was used in data analysis. Results The ST imaging was symmetrical. The radioactivity was higher in the ST front area than that of the back area. The average uptake ratios of ST/CB, LST/CB, RST/CB were 1.71±0.16,1.70 ± 0. 16 and 1.72±0.17 respectively, in which the three ratios of the female were 1.74 ± 0. 18, 1.71±0. 19 and 1.76 ± 0. 19 respectively and those of the male were 1.68 t 0. 14, 1.68 ± 0. 13 and 1.69± 0.15respectively. ST/CB, LST/CB and RST/CB were negatively correlated with patients'BMI (r = -0. 53,-0.57,-0.47, all P＜0.05). The ST/CB was negatively correlated with patients' age(r=-0.39, P=0. 03). The multiple linear regression analysis showed that the BMI was significant independent variable (β=-0.53, t= -3.36, P=0. 002). Conclusions TheSTDAT,evel may decrease as patients' BMI and age increase. Females' DAT level is slightly higher than males'. For ST DAT imaging, age, gender and BMI should be all taken into consideration.