Greenhouse gas emission from burning rice straw on file in the Mekong delta of Viet Nam was investigated by prepared questionnaires and field surveys in An Giang, Dong Thap, Kien Giang and Can Tho provinces. The results showed that the most common method to remove rice straw is field burning while other methods such as burying, cultivating mushroom, selling, raising cattle, giving away and leaving on fields accounted for the small proportion. Removing rice straw methods vary depending on the rice crop seasons. The estimated quantity of rice straw in the Mekong Delta region is approximate 28.98 million tons in 2014, in which 27.68 million tons is burned directly on the fields. The survey indicates most rice farmers tend to continue burning straw as the most popular method in the next few years. This practice releases into the atmosphere with about 32.42 million tons of CO2, 768.40 thousand tons of CO and 68.65 thousand tons of NOx. The amount of CO2 accounting for more than 97% of the total greenhouse gas released from field burning. Studying on the methods to utilize the straw after harvests is highly recommended in order to limit the straw burning activities which waste a biomass resource and causes environmental pollution.