Keywords:Venus, carbon monoxide, meridional circulation
We constructed a model which calculates the meridional distribution of some minor chemical species such as CO, H2O, and H2SO4 in the Venus' atmosphere. Our model consists of chemical reactions, advection, diffusion, condensation/evaporation, and sedimentation of cloud particles. The atmospheric temperature and density profiles are fixed, and a steady one-cell structure of the meridional circulation in each hemisphere is assumed. A steady state distribution is numerically solved by using time-marching.