The aim of this study was to monitor agricultural land use change in Amphoe Lam Thap, Krabi Province between 2000 and 2009 using Geographic Information System, and to examine the change before and after the National Government Policy implementation for massive oil palm expansion with an aim of achieving 10 million rai by 2029. Results show that oil palm areas increased significantly from approximately 20 sq km (12,500 rai) in 2000 to 86 sq km (53,750 rai) in 2009. Its expansion was by a factor of four during the ten-year period of study. Oil palm cultivation has expanded mostly by replacing para rubber plantation area (61.2 sq km; 71.6%), other agricultures (5.2 sq km.; 5.2%), and forest (3.7 sq km.; 4.3%), respectively. Evidence of strong policy implementation and enforcement was marked in the present study. Strict policy on agricultural land use in this area is essential to maintain healthy environment and ecosystem.