The vapor pressures of dimethyl phosphite in the range of (352.9 to 443.4) K and dimethyl methyiphosphonate in the range of (358.2 to 453.5) K were measured by a static method. The vapor pressure data were fitted to the Antoine equation. The vapor pressure data of dimethyl phosphate and dimethyl methylphosphonate were compared with literature Values. The average relative deviations of vapor pressure fitting for dimethyl phosphate and dimethyl methylphosphonate are 0.52 % and 0.68 %, respectively.