Viet Nam is still an agricultural country because a half people are working in agricultural sector. The total rice export pass to more than seven billion US dollars in 2021 that takeovers of nearly 17% of the one of agricultural production export of the country. Mekong Delta is considered the granary of Vietnam. With a total paddy area of 4.07 million ha, the annual rice production was 24.3 million tons, accounting for half of Viet Nam rice production. The rice production in the Mekong Delta is done mostly by machines that use mostly diesel oil and gasoline for operation. For rice farming in Mekong Delta, the level of power equipped is around 3.17 HP/ha. Obviously, the application of machines in rice farming has a lot of advantages. However, it is also contributing to increase the greenhouse gases emissions from burning fuel (direct emission) and manufacturing (indirect emission) of the machines in our earth that cause of rising temperatures, unpredicted weather events, and some of other impacts referred to generically as ‘global warming’. This paper studies the impacts of using machines in paddy production mechanization in Mekong Delta of Viet Nam on the greenhouse gas emission. The results indicate that the direct CO2 eq. emission in rice farming operations is 0.22 ton/ha per cropping season and the indirect CO2 eq. emission is 0.02 tons/ha. With the paddy area of 4.07 million ha in the Mekong Delta, total CO2 eq. emission from mechanization in rice farming corresponds to 733,000 tons/year.