Abstract: The pathogens and their occurrence rhythm of bamboo leaf rust in Nanjing were studied. The bamboo leaf rust mainly has three types of the pathogens, namely Puccinia phyllostachydis, Puccinia longicornis and Uredo ignava. The overwintering of P.phyllostachydis and P.longicornis were mainly as the mode of teleutosorus on bamboo leaf. The primary infection source of the pathogens is the urediospore produced by the mycelium under the teleutosorus, and the primary infection of P.phyllostachydis also includes the few uredinium that can live through the winter. The bamboo leaf rust has an incubation period of 10—15 days. After several infections by urediospores, the conditions of the disease reach peaks from June to October. During the process, heteroecism never occurs.