The variability of biomass and carbon stocks in forest ecosystem is influenced mainly by altitude, slope aspect, species composition, and structure, as well as management history. The study was conducted to understand the whole array of variation among five different elevation classes ranging from 400-3000 m asl as well among North and South aspects at the same elevation in Sirmaur district, Himachal Pradesh (Western Himalaya). A total of 30 plots (3 replicates in each forest type) were studied, where each plot represents 10 quadrats of 10 x 10 m size were laid to calculate forest biomass and carbon stocks. The values for Biomass density were in the range of 123.89 +/- 26.33 to 537.77 +/- 56.34 Mg ha(-1) whereas, Carbon density were in the range of 58.23 +/- 14.33 and 252.75 +/- 24.98 Mg ha(-1). The conifer forest types showed an increased amount of carbon density than broad-leaf forest types, but overall broad-leaf species contributed to more carbon stocks in the studied region due to absence of conifer species in lower elevation class. Protection of conifer species, especially Cedrus deodara that were found to contribute maximally to total carbon stocks could be very helpful in carbon sequestration. Also, old-growth individuals for both conifer and broad-leaf should be protected as they have high carbon accumulation potential, therefore, recommended for management in such sites. The outcomes of the current study could be useful in understanding the distribution of carbon stocks in sub-tropical and temperate forest types having similar species composition.