Forest resource is the important material foundation of national sustainable development. And it need to master the status
and change of forest resource timely for reasonable exploitation of forest and its renewal. Laos is located in the heart of
the Indochinese peninsular, in southeast Asia, latitude 14° to 23 °north and longitude 100°to 108°east, covered a total
236, 800 square kilometers, and country of nearly 6 million people. The forest of Laos dropped from close to two-third
in the 1970's to less than half by the 1990's. This deforestation has been attributed to two human activities : a
traditional of shifting cultivation or slash and burn farming, and logging without reforestation. Remote sensing and GIS
are the most modern technologies which have been widely used in the field of natural resource management and
monitoring. These technologies provide very powerful tools to observe and collect information on natural resources
and dynamic phenomenon on the earth surface, and ability to integrate different data and present data in different formats.
In this study, using forest cover map and Landsat 7 ETM data, we analyze and compare forest cover change from
1997 to 2002. And the maximum likelihood method of supervised classification was used to classify the remote
sensing data, we processed Spectral Enhancement, including Normalized Difference Vegetation Index (NDVI) ,and
re-classify data again base on Principle Components Analysis (PCA) and NDVI.