Abstract: To determine the biological characteristics of Bipolaria maydis in Fujian Province, three B. maydis isolates, collected from Jian’ou, Shaxian and Fuzhou areas, were selected as research objective. The effects of temperature, moisture, pH values, light and nutrition on the mycelial growth, sporulation quantity and conidia germination were studied. The results showed that the optimum temperature and pH value for mycelium growth were 30℃ and 6; the optimum temperature and pH value for spore production were 25℃ and 6-7; and the optimum temperature and pH value for conidia germination were 25-28℃ and 6. Light could significantly inhibit the sporulation. Under the condition of relative humidity of 85%, 95% or on water agar, the percentage of conidia germination reached 50% , 88% and 90% , respectively. Glucose, lactose, mannitol and soluble starch were suited for mycelial growth and sporulation. However, urea, ammonium sulphate, ammonium nitrate, ammonium chloride could significantly inhibit the mycelial growth, spore production and conidia germination. The lethal temperature for hypha was 65℃ for 10 min or 60℃ for 30 min, while the lethal temperature for the spores was 60℃ for 10 min or 55℃ for 30 min. Three isolates were obviously different in characteristics of sporulation, lethal temperature of hypha and the pathogenicity.