Abstract: Using historical data of forest resources inventory and regional planning information of Jiangsu province, a provincial population is stratified. Then, field work was conducted in randomly selected sampling plots in the strata where annual changes are obvious, while in the stratum where changes are not obvious, data from the field inventory data in previous year are directly referenced and stratified sampling estimation is carried out. In this way, annual updating of NFI data is realized at lower costs. This paper also carries out an experimental research by using the 2000-2005 inventory data of Jiangsu province, and the results show that it is feasible.

Key words: NFI, annual data updating, stratified sampling, area estimation, volume estimation, sampling precision