Goals: Determining the rates of Refractive errors and studying the correlation between the Refractive errors and the obesity state of high school students in Phu Tho province to suggest the preventative solutions. Objects and Methods: Study the cross sectional study on secondary school pupils by areas in Phu Tho province. Results: The rate of Refractive errors of pupils in Phu Tho province is 22.45 percent, which is quite higher than general national rate. For more details, the rate at the city is 39.33 percent, higher than at mountain regions 11.64 percent and midland regions 13.55 percent. This difference is significantly statistical with p0.001. The percentage of pupils in overweight and obesity groups with refractive errors is 31.48 percent (17/54), which is 22.16 percent (385/1737) higher than normal and low-weight groups. The difference is statistic with (X exponent 2