Abstract: Based on the data from forest inventory in 2000 and 2015, the arbor forest carbon storage and carbon density in Huili County of Sichuan Province were estimated using the biomass expansion factor method. The results showed that Over the past 10 years, the total carbon reserves of arbor in Huili County exhibited a significant increase, which was a small carbon sink.The largest carbon reserve of the arbor forest was Pinus yunnanensis,which accounted for 49.37% of the total carbon reserves. The carbon storage of different ages from high to low were:near-mature forest > mature forest > middle aged forest > overmature forest > young forest.The carbon sink function of different trees at the same age were different.