The research aims at collecting basic data with the participation of farmers in the Mekong Delta – Viet Nam; then proposes solutions to enhance farmers' capability in bio-diversity management, which help ensure household food security for the future. Also, in the research, the group of researchers has focused on agricultural manufacturing efficiency, food security, and plant diversity at the household level. The PRA - Participatory Rural Appraisal and Questionnaires method was used in this research. The result of the research showed that the main resource of farmers' income within is from grain rice production, accounting for 95.2% in An Giang province, 74.4% in Hau Giang province, and 87.9% in Soc Trang province. The division of labor in terms of gender is relatively reasonable. It has also been found out that farmers have considerable knowledge of household food security; that plant diversity is decreasing as agricultural products are subjected to change towards market needs (24.3% in An Giang province, 27.1% in Hau Giang province, and 33.3% in Soc Trang province). Besides, the research results also showed the fact of food insecurity and how households react in case of food insecurity.