This paper adopts different technologies to integrate both the supply and demand-side options in the power sector of the selected GMS countries for restricting the CO2 emissions under the perspective of the nationally determined contributions (NDCs). This study develops three mitigation scenarios including the Business-as-Usual (BAU). The BAU scenario is established based on the current trend of electricity consumption associated with the socio-economic development of the selected GMS countries. The CO2 mitigations in the MIT01 scenario are in line with the power development plans (PDP) whilst the MIT02 scenario is formulated by enhancing renewable energy utilization, energy efficiency improvement, carbon capture and storage (CCS), and nuclear power. The Low Emissions Analysis Platform (LEAP) model is employed for the estimation of electricity demand, generation, and GHG emissions between 2015 and 2030. Results show that in 2030 under the MIT01 and MIT02 scenarios, the CO2 emissions can be reduced by 85.22 MtCO2eq and 149.24 MtCO2eq, respectively. Additionally, the study is extended to 2050 showing the total CO2 emission reduction in the MIT01 and MIT02 would be decreased by 26.41% and 68%, respectively compared to the emissions in the BAU. However, the goal of the Paris Agreement required higher GHG emissions deduction in 2050 than those in the MIT01 and MIT02 scenarios.