近成熟的桃果实预先以软腐病菌（Ｒｈｉｚｏｐｕｓｓｔｏｌｉｎｉｆｅｒ）孢子悬浮液接种，再以５、１０ｍｇ／ｍｌ脱乙酰壳多糖处理后，室温下贮藏４～８天，４℃下贮藏３０天，防治效果明显，４或８天后的防效与０５ｍｇ／ｍｌ的杀菌剂施宝克相当。室内离体培养发现脱乙酰壳多糖对桃软腐病菌（Ｒｓｔｏｌｏｎｉｆｅｒ）和桃褐腐病菌（Ｍｏｎｉｌｉｎｉａｆｒｕｃｔｉｃｏｌａ）的菌丝生长、孢子形成有明显的抑制效果。试验还发现高于２ｍｇ／ｍｌ的脱乙酰壳多糖能诱导这两种病菌的形态学变化，表现为菌丝过度分枝、肿胀，菌体细胞变短，分隔增多；Ｒｓｔｏｌｏｎｉｆｅｒ畸形的菌丝还产生质壁分离等现象。两者比较Ｒｓｔｏｌｏｎｉｆｅｒ形态变化比Ｍｆｒｕｃｔｉｃｏｌａ显著，而抑制试验却表明后者对脱乙酰壳多糖更为敏感 Nearly mature peach fruit was inoculated with Rhizopus stolinifer spore suspension in advance, then treated with chitosan at 5 and 10 mg / ml, stored at room temperature for 4 to 8 days and stored at 4 ℃ for 30 days, and the control effect was obvious , 4 or 8 days after the control effect and 0  5mg / ml bactericide Shi Boke quite. In vitro culture showed that chitosan had a significant inhibitory effect on mycelial growth and sporulation of Rstoolonifer and Moniliniafructicola. The experiment also found that chitosan higher than 2mg / ml could induce the morphological changes of the two pathogens, which manifested as excessive branching and swelling of mycelium, shortening of cells in the mycelia and increasing separation. Rstoolonifer mycelia Also produced plasmolysis and other phenomena. The morphological changes of R.stolonifer were more pronounced than those of M.fructicola, whereas inhibition tests showed that the latter was more sensitive to chitosan