A study was conducted at Hoa An campus of Can Tho University to determine green house gas emissions of Lai Sind cattle, which were measured by the ventilated hood system designed by JIRCAS (Japan International Research Center for Agricultural Sciences). There were 3 trials carried out on 4 Lai Sind cattle fed the same diet. Each experiment was 14 days including 9 days for diets adaptation and 5 days for sampling. The green house gas emission was measured in two consecutive days. In the first experiment, cattle were fed 70% Hymenachne acutigluma and 30% Brachiaria mutica in fresh matter. The results showed that the production of CH₄ was from 74.4-109 L/day/animal and 27.8-31.7 L/kgDMI/day. In the second experiment, cattle were fed 50% Hymenachne acutigluma and 50% Brachiaria mutica in fresh matter. The CH₄ productionwas from 83.6-107 L/day/cattle and 22.0-26.4 L/kgDMI/day. In the third one, cattle were fed 5 kg Hymenachne Acutigluma  and 5 kg Brachiaria Mutica (fresh matter), 1 kg concentrate and rice straw fed ad libitum. The methane emission was from 93.2 to 127 L/day/cattle and 26.6-32.6 L/kgDMI/day. It could be concluded that the head chambers system designed by JIRCAS could be operated well and gave the good results.