Behind the autopsy of 249 dogs in Phu Tho, the results showed that: determined three of nematode on dogs in Phu Tho province. They parasited mainly in the small intestine, stomach and large intestine. There was one species of Anisakidae family Skjabin and Karokhin, 1945
the one species of Ancylostomatidae family Looss, 1905
one species of Spiruridae family OerIey, 1988. The prevalence of three species of nematoda were found: Ancylostoma caninum (Ercolani, 1859) was highest, with genaral prevalence was 40.96 percent
Toxocara canis (Werner, 1782) was 29.72 percent, and the lowest in Spirocerca lupi (Rudolphi, 1809) was 4.82 percent. This article describe three nematoda species of dog in Phu Tho province.