Abstract: The biological characteristics and host range of Athelia bombacina，a newly discovered fruit rot pathogen of pear，were studied. The results showed that the optimum medium for hyphae growth of Athelia bombacina was potato dextrose agar（PDA），the optimum temperature was 25 ℃，the optimum pH was 7，and dark treatment was beneficial to hyphae growth. The lethal temperature for hyphae was 54 ℃ for 10 min. The optimal germination temperature of the spores was 20 ℃，the optimum pH was 6，and the best carbon source was glucose. The effect of light on spore germination was not obvious. The lethal temperature for spores was 52 ℃ for 10 min. Based on studying the spore production under different conditions，the best culture conditions for spore production of the strain were as follows：medium formula：15 g of oat，15 g of agar，10 g of glucose，2 g of glycine，0.5 g of CaCO3，2 g of NaCl，1 000 mL of water，and pH adjusted to 6，alternating light and dark，low temperature induction and high humidity more than 95%. The determination of host range for Athelia bombacina showed that，Athelia bombacina could infect not only pears，but also apples，strawberries，cherries，nectarines，apricots，and jujubes；however，it did not infect blueberries，grapes，oranges，or kiwifruit etc. The ability to infect hawthorns，oranges，and pomelos was weak，and the infection of tangerines and pomelos was limited to the peel——Athelia bombacina could not penetrate into the pulp tissue. Athelia bombacina had different infection abilities with different pear and apple varieties.

Key words: pear, postharvest fruit rot, Athelia bombacina, biological characteristic, host range