The growth of vitamin C single crystals was studied by direct observation. In flowing solution

the linear growth rates of three orientations (［010］

［001］

［100］) were measured for vitamin C-water system. The experiments were designed as orthogonal test to investigate the effect of various factors. Comparing with temperature and velocity

supersaturation is the most important factor. And the relations between growth and supersaturation were different with crystal directions

which obviously show anisotropy. The order of magnitude of G［010］

G［001］

G［100］ and their dependency on supersaturation (g［010］

g［001］

g［100］) were in good agreement with analysis of maximum difference. The effect of solution diffusion could be neglected and crystal growth was controlled by surface reaction. According to the growth models

the growth mechanism was discussed.