The aim is to prepare esomeprazole magnesium enteric coated particle system type tablet, and to investigate release rate in vitro of it.The enteric coated particle system type tablet was prepared by direct compression process.Using pellets roundness, compressibility, hardness, flowability and accumulative release rate as index, fillers, materials and weight gain of enteric coating film, addnl. excipients were optimized to confirm the formulation.The optimal formulation was as follows: avicel PH101 as pellet core filler, particle size of 0.5-0.8 mm, mixture of acrylic resins Eudragit(R)NE30D and Eudragit(R)FS (2:1) as coating material, weight gain of 25%, avicel PROSOLV90 as addnl. excipients.Accumulative release rate of the samples was lower than 5% in pH 2.0 HCl solution within 2 h and more than 95% in pH 6.8 PBS within 30 min.The preparation formulation is reasonable and feasible, and the accumulative release rate of the preparation is in line with the requirements.