Advances of agroforestry are known to provide rural people much potential in both struggling out their poverty and mitigating of firm damaged caused by uncontrollable weathers. Changing of cultivation systems from single annually plant cultivation to multi-specie cultivation with various trees and perennial woody plants included can reduce the severities of climate change by capturing more atmospheric carbon dioxidejg and converting into woody and soiled biomasses. Canopy difference works better in hedging the areas from erratic and extreme climates. Beyond traditional timber and non-timber products, cultivations with agroforestry system also provide farmers a new valuable product which is tradable m certain markets; the carbon. The carbon, a kind of greenhouse causing gas trapped in biomass form, can be counted and amounts of it can be possibly traded at present. This paper describes the efforts of an intensive Web-Based GIS applications for agroforestry carbon sequestration offset project in Thailand.