We study the macroscopic drying pattes of aqueous suspensions of colloidal silica spheres. It was found that convection strength can influence patte formation. Uniformed films are obtained at weaker convection strength.In addition, we make clear that it is not reasonable to discuss individually the effect of temperature and humidity on the colloid self-assembly. The physical mechanism is that these factors have relationship with the evaporation rate, which can affect the convection strength.