The boundary layer condition and describing equation of boundary layer for solute transport are studied in this paper. A small flux is defined as the representive value of boundary layer. Laplace transfer method is used to solve the concentration of boundary-layer problem (CSBL). The comparison of CSBL with the exact solution is conducted. Results show that the CSBL is in good agreement with the exact solution. An important application of the theory is the estimation of transport parameters of solute transporting through porous materials. This leads to a new method for the estimation of parameters by using the observation imformation of the advance of the boundary-layer with time. This new method is simple, saving time and can suffieiently utilize the observation data of boundary layer transport.