Abstract: In order to discussing enzymology mechanism of dwarf、 affording theoretical basis to choose and breed excellent dwarf cultivars which have the virtues of dwarf density planting、high quantity and quality, the general type of peach “Chunyan”，spur type “Super red spur” and dwarf type “P.persica var.densa ” were used to study the correlation between correlative enzyme activity of POD、SOD、CAT in leaves of peach and length of internodes in different growing type peaches．The results showed that the enzyme activity in different type peach leaves had similar changing rule; the activity difference of POD、SOD、CAT in leaves of peach among different type peaches all achieved fearfully marked level; the correlation between the enzyme activity and dwarf level was tight, and the enzyme activity of dwarf type in peach leaves>spur type >general type; it had marked negative correlation between the activity of POD and length of internodes in three types peaches、the activity of SOD and length of internodes in “Super red spur”、the activity of CAT and length of internodes in “P.persica var.dens ”. So the activity of POD can be considered as an index in choosing dwarf cultivar.