Abstract: The white rust,caused by Puccinia horiana was one of the most important epidemic diseases on Chrysanthemum,and also was a quarantine action pest in the world.Trials determined the teliospores germinating biology of P.horiana : the teliospores were germinated between 4 ℃ and 32 ℃,while the optimum temperature range was 15 ℃ to 24 ℃,especially between 18 ℃ and 21 ℃.Water was necessary for the teliospores germination.Without free water,it couldn't germinate in 24 h,even with 100 % R.H.The propriety of pH for germination was pH 4 to 6.5, while pH 6 was the most favorite.2 % glucose solution promoted the germination of the teliospores evidently,whereas the fresh juice of chrysanthemum foliages restrained it prominently.Light didn't influence on the germination.