This study aims to make an inventory for the greenhouse gases (GHG) emissions (carbon dioxide, methane, nitrous oxide) in the Sultanate of Oman, in the period of 2000 to 2015, by answering a series of questions based on calculating the annual increase of emissions until 2030, and find out the total emissions from the four economic sectors: (energy, agriculture & land use, waste, industrial processes), and measuring the disparity between the energy activities on generating these emissions, and finally find the solutions that contribute to the reduction of emissions of greenhouse gases in the Sultanate of Oman in the future. The methodology of this study depend on several types of data and information such as: the annual reports of the Authority for Electricity Regulation, Statistical Yearbook, data from the Oman Oil Refineries, data on livestock emissions and fertilizer management, and data of waste from IPCC Guideline 2006. This data was entered, managed, and analyzed using IPCC software, and EFFECT software, Finally, the total emissions where divided by Sector type, and fuel type. The results of the study concluded that the total GHG emissions from the four economic sectors in 2015 was 69,612 Giga gram (Gg), but it can increase to 98 172 Giga grams by 2030. In addition, the results showed that the energy sector reached a percentage of 78.2% from the total emissions in 2015, which was the highest among other sectors. The largest total emissions from the energy sector is resulting from electricity generation with a total estimated to be around 14972.6 Giga gram equivalent of carbon dioxide, that's mean 33% from the energy sector. Thus, the study recommended to do some solutions to mitigate the increase of GHG, and develop the renewable energy projects. And also, create the green buildings and the sustainable transportation, and increase the green areas to build a net carbon sink.