A series of experiments were conducted to study the mutation of Kloechera apiculata by many kinds of treatments such as UV and UV+LiCl. The optimal dosage disposal was determined: 15 W 30 cm under Ultraviolet irradiation for 20 s, UV+LiCl under Ultraviolet irradiation for 20 s and added LiCl 0.3% (w/v). One strain (UV20-13) which had obvious physiological characteristic was obtained. the incidence of blue and green mold of citrus was reduced by 25.56% and 10.00% in vivo experiment after 7 days respectively. The strain UV20-13 was tested by the experiments of subculture and dynamic growth, and the results showed that the strain UV20-13 was better than K.apiculata in the growth characteristics, and it did not appear retrogression, reversion mutation ect after subculturing 10 generations. Therefore the strain UV20-13 had genetic stability.