Abstract: Seasonal changes in in soil respiration and its relationship with microbial population was studied in sub-tropical mixed oak forest ecosystem of Kounu Hill, Senapati District, Manipur, located at a distance of 25 km from Imphal city which falls at 93°55´E longitude and 24°54´N latitude at an altitude of 941 m from mean sea level by using alkali absorption method .The rate of soil respiration was highest during the rainy season (345.98 mg CO2 m-2 hr-1) and minimum during the winter season (195.71 mg CO2 m-2 hr-1). The microbial population i,e bacterial and fungal population showed a significant positive relationship with the rate of soil respiration. The microbial population was maximum in rainy season and minimum during winter. Abiotic variables (i,e. soil temperature, rainfall, relative humidity, air temperature and soil moisture) also exhibited a positive significant relationship with the rate of soil respiration.