Objective: Establish the method of isocratic elutriate by hplc for different positions of Pileostegia tomentella, compare the difference of different positions of Pileostegia tomentella. Methods: extract Pileostegia tomentella by 70% ethanol, use different proportions of methanol and acetonitrile systems to isocratic elutriate; C18 column (4. 6mm ×250mm, 51μm) ; flow rate at 0. 8ml/ min, sample volume is 10μl; Results: methanol -water (40: 60) could separate different positions of Pileostegia tomentella. Chemical composition in diffe...