Abstract-Seasonal variation of phyllospheric bacteria and their leaf traits of four woody species of subtropical environment were studied at Shivapuri Nagarjun National Park. The four species examined were Alnus nepalensis D. Don., Schima wallichii (DC.) Korth., Rhododendron arboreum Smith. and Gaultheria fragrantissima Wall. The first species is deciduous, second is semi-deciduous and other two are evergreen. The leaf samples were collected during summer and winter seasons in 2010. The estimation of bacterial population was done by the serial dilution plating method using Nutrient Agar Glycerol Medium. The leaf traits such as leaf water content, nitrogen content, phosphorous content, sugar content and specific leaf mass were also estimated. The bacterial population of four woody species ranges from 2.87 to 5.48 log CFU per g f.w. The epiphytic bacterial populations differed among seasons and among species. In subtropical environment bacterial population was found to be limited to leaf phosphorous content.