A method of ultrasonic simulation based on the FIELD II software platform for carotid artery plaque was proposed according to the analysis for geometrical shape,tissue characteristics and acoustic properties of carotid artery plaques in clinic,and then a simulation system was developed by using the MATLAB graphical user interface(GUI).In the simulation and development,a three-dimensional geometric model of blood vessel with plaques was set up by using the metaball implicit surface technique,and a tissue model was established based on the scatterers with spatial position of gamma random distribution.Comparison of the statistical and geometrical characteristics from simulated ultrasound B-mode images with those based on clinical ones and preset values,the results fully demonstrated the effectiveness of the simulation methods and system.