Using of Geo-Informatics and Google Earth Engine (GEE) technology provide the smart system to access the land information that is very important to achieve the country's goals on Climate change. The purpose of this research were to develop the land use change monitoring system by integration of Geo-Informatics and the GEE technology and to create the spatial GHG emissions and removals datasets in Chiang-Mai. Four periods (2019-2021) of Landsat-8 and Sentinel satellite imagery were used to interpret land use and land use changes. Main types of land use change based on amount of biomass were analyzed: forest land, cropland, grassland, wetland, settlement and others land. Cropland are divided into 4 sub-groups base on amount of biomass: rice fields, rubber, oil palm and other agriculture. Then the datasets of land use change were used to assess the amount of greenhouse gas emissions and reduction using the calculation method referring to the IPCC Good Practice Guidance for LULUCF (GPC) and 2006 IPCC Guidelines for National Greenhouse Gas Inventory. The results of the study are summarized as follows: Chiang Mai Province abundant with forest areas accounted for 69.9 % of the total area. There is a national forest national park and many wildlife sanctuaries. According to the interpretation of satellite images, it was found that Chiang Mai has continued to expand urban areas and agricultural areas. Most of the land has been transformed from abandoned grasslands. It wasn't modified from the forest area as in the past. This is due to the measures of forest preservation and reforestation. As a result, GHG emissions are reduced. The analysis results show that when deducting the emission value from the amount of greenhouse gas storage, Chiang Mai Province has GHG storage of -967,349.16 tCO2 -1,308,790.00 tCO2 -1,277,804.35 tCO2 in 2019, 2020 and 2021 respectively. The results of this study are used as supporting information for the project to develop an approach to reduce GHG at the area base. This is another step forward in using geospatial technology to assess and manage carbon. This makes it possible to show the amount of GHG in the form of a map. Including the ability to identify emissions or reservoirs of GHG as well. The developed GHG monitoring system will benefit government agencies or the private sector to formulate more efficiently targets for reduction implementing projects.