Aims The overall goal of this study was to examine the spatial and temporal patterns of C storage from 1992 to 2002 in forest ecosystems in Guangdong, China. Methods We used 2237, 2103, and 1978 plot data from three continuous forest inventory in 1992, 1997, and 2002, respectively, four TM images and one soil survey data in Guangdong to examine the spatial and temporal patterns of C storage in forest ecosystems during 1992-2002. The uncertainty analysis of forest C storage in Guangdong in 1992 and 2002 was also conducted to provide the range of estimations. Results The forest coverage percent in Guangdong increased from 37.1 % in 1992 to 57.2 % in 2002 while the total forest C storage in Guangdong increased from 144.73 ±6.20 Tg in 1992 to 215.03 ± 8.48 Tg in 2002. The order of average forest biomass C storage increase during 1992-2002 among the four regions is Western Guangdong (GW)>Eastern Guangdong (GE)>the Pearl River Delta (PRE)>Northern Guangdong (GN). The factors including tree species and altitude and slope aspect can explain 58-67 % variation of Veg C storage multiple regression model in Guangdong. However, the multiple regression model for SOC storage can only explain about 18-39 % variation of SOC storage in Guangdong. Total ecosystem C is mainly determined by SOC storage. Conclusions The total forest C storage in Guangdong increased about 49 % from 1992 to 2002 partially due to the increasing forest coverage percent over the period. The spatial distribution of forest C storage in Guangdong was uneven and this pattern reflects differences in forest management and economic and social development. Future forest management should focus on the selection of tree species, management of forest stand structures and implementation of sustainable practices so that Veg C sequestration potentials can be maximized.