Optical turbulence forecast plays an important role in optical engineering applications; however,no related work has been reported yet in China. Mesoscale weather forecast model MM5, its flow chart and coordinate system are introduced; based on its result with Dewan optical turbulence parameterization, 48 hours' refractive index structure constants of Hefei, Kuerle and Dongshan are forecasted, and turbulence profiles of every time record and profile charts of refractive index structure constant are shown. The results consist with normal characteristics of magnitude and tendency of refractive index structure constant varying with height, but there are differences among these places. Brief analysis is given to explain these differences.As there is no comparison with observations, the results need to be further checked by experiments for future applications.