Abstract: The formation and development of radiation fog through the one-dimensional numerical model are studied. The results are as follows: (1) Fog can change the ambient field, vice versa, the ambient field may influence the fog. (2) The model fog forms initially at the level apart from the surface. The explanation is given in the paper. (3) The turbulence delays the Fog formation but promotes the fog developing. (4) Whether the liquid water content exchange coefficient equals to momentum exchange coefficient or not, has no influence nn the numerical results. In addition, wind, temperature, exchange coefficient, net radiative flux,etc, before; and after the formation of radiation fog have been studied.