318 serum samples of buffaloes were collected from Thai Nguyen, Ha Giang, Cao Bang and Son La provinces during 2012-2013. The serum samples were analysed to identify the Toxoplasma gondii infection rate of buffaloes through Latex testing method. The analysed result showed that the T. gondii infection rate of buffalo in general was 33.96 percent. Of which, the rate was 54.48 percent in Ha Giang province, 44.90 percent in Thai Nguyen province, 9.52 percent in Cao Bang province and 10.8 percent in Son La province. The infection rate of buffalo from 1.2 to 2 years old was 20 percent , from 3-5 years old was 50 percent, from 6-15 years old was 27.78 percent. The infection rate of female buffalo was 40 percent and male buffalo was 28.90 percent.