Abstract：The more common situations both in field and in laboratory involve nonorthogonal fractures of unequal aperture. The effect of crack shape in stagnant pool on solute tracer and the corresponding change of transport character are discussed especially. Random tracer particle method is adopted，which considers convection and diffusive steps. Numerical experiments are conducted in a homogeneous conductivity field. Simulations with different degrees of diffusion are used to compare their effect on solute transport result，i.e. character of breakthrough curves. The effects of geometric shape of fracture in stagnant pool and relative molecular diffusion degree on the solute transport are analyzed according to the characters of different breakthrough curves. Results indicate that，in the single fracture without stagnant pool，the solute pours out almost at the same time；for the same diffusion scale，the peak value of the breakthrough curves of the fractures with a deeper or wider stagnant pool decreases obviously and the tail of the curve increases. The results also demonstrate that the breakthrough curves have similar characters under the condition of higher scale of molecular diffusion.
