Effects of different temperature, light and pH on the mycelium growth and spore germination of Phyllosticta chlorospora McAlp of Prunus armeniaca L. were studied in the paper. The results showed that the optimum pH for mycelium growth was 7 to 10, the best temperature for mycelium growth was 30℃, and full sunlight was the most suitable for mycelium growth. The optimum pH for spore germination was 4 to 7, the optimum temperature for spore germination was 25℃ to 35℃, and full sunlight was the most suitable for spore germination.