The invention provides an atherosclerotic plaque classifying system. The system comprises an angiography device which is used for acquiring a vascular ultrasound contrastographic image, a basic parameter acquisition device which is used for analyzing the vascular ultrasound contrastographic image to acquire the maximum plaque area A, an intraluminal time-intensity curve and an intra-plaque time-intensity curve, extracting the intraluminal contrast agent peak time TTP1, the peak intensity IMAX1 and the area under the curve AUC1 from the intraluminal time-intensity curve, and extracting the intra-plaque contrast agent peak time TTP2, the peak intensity IMAX2 and the area under the curve AUC2 from the intra-plaque time-intensity curve, a plaque quantitative parameter calculation device which is used for acquiring the enhancement intensity IMAX, the maximum enhancement density DMAX, the relative peak time delta TTP, the area under the curve delta AUC and the relative average transit time delta mTT, and a classification result output device which is used for classifying atherosclerotic plaques according to the plaque quantitative parameter.