OBJECTIVE： To optimize the ultrafine pulverization technology in Chaige tuire powder； to compare the content and microcharacteristics between ultrafine powder and ordinary powder. METHODS： Using contents of 3 active ingredients （puerarin， glycyrrhizin and baicalin） and powder d（0.5） as main indexes， bulk density， angle of repose and microcharacteristic as reference indexes， orthogonal test was designed to optimize the initial particle size， moisture and pulverized frequency in ultrafine pulverization technology. Contents of 3 active ingredients of ultrafine powder and ordinary powder （over 65/80 mesh sieve） and observation results of calcium oxalate crystal under microscope were compared. RESULTS： The optimized technology was as follow as over 65 mesh sieve， moisture of 2.5％ preliminary powder in 60 Hz of frequency for pulverization. In verification test， d（0.5） average value of 3 ultrafine powder samples was 31.5 μm （RSD＝0.45％， n＝3）； contents of puerarin， glycyrrhizin and baicalin were 0.232 mg/g （RSD＝1.31％， n＝3）， 0.212 mg/g （RSD＝1.62％， n＝3）， 8.962 mg/g （RSD＝0.89％， n＝3）， respectively， which were increased about 30％-40％ than in ordinary powder （0.158， 0.156 69， 6.140 mg/g）. There were no or little bundles of calcium oxalate crystal that is common in ordinary powder. CONCLUSIONS： Optimized ultrafine pulverization technology is stable and feasible； contents of 3 active ingredients in Chaige tuire ultrafine powder are higher and calcium oxalate crystal are litter than ordinary powder， which possibly reduces the adverse reactions in clinical application.