Abstract: The characteristic of farinfrared drying on biological product is different from that of convective hotairflow drying. The temperature at different position in farinfrared dryer is different. The experiemental research under three working conditions，e．i．， only circulating fan working or only wetexhaust fan working or circulating fan and wetexhaust fan simultaneously working， and the analyses of standard difference and variation coefficient on the dehydrating rate and dried quality of xianggu mushroom in farinfrared dryer show that there are certain uneveness of dehydrating rate and the dried qualities of xianggu mushroom placed at different positions are different. The circulating fan and wetexhaust fan must be installed in farinfrared dryer for xianggu mushroom. While the circulating fan and the wetexhaust fan are simultanneously working, the drying uniformity will be improved.