Grouting is a method by which the injection fluid penetrates the fractures and pores and improves the mechanical properties of ground. As a result, the permeability and deformability are decreased and strength is increased. In this study, we tried to estimate the grouting take of a fractured rock mass based on a forward numerical explicit algorithm. In this case, initial injection pressure and frictional loss of pressure due to the rheological parameters of the injection fluid, the geometric characteristic parameters of rock joints and grouting time are controlled the grouting intake. The measurement criterion in this study is the volume of grout spread and the length of slurry penetration in fractures. In this study, we first examine the relations between the propagation problem and the slurry penetration in fractures and their proof process will be expressed. A computational code which takes into account the grouting operations in fractures in various states such as horizontal and inclined single fractures, and also multiple fractures is developed. Grouting in a well with cross-linked and sequential joints has been analyzed at various depths. Since numerical modeling is very useful for saving time and cost of injection operations, in this study, using this code, it was observed that by increasing the aperture value from 0.5 to 2 mm, the penetration rate is increased up to a 9 times and this parameter has the greatest influence on the length of grout penetration. While injection pressure of grout controls the slurry diffusion and volume of grout spread. The behavioral parameters of injected grout such as viscosity are inversely proportional grout penetration. If the density of the grouting fluid is increased, penetration rate is increased in the direction maximum slope in oriented fractures but in the opposite direction, grout penetration rate is drastically decreased. The time of grouting operation controls the optimal slurry flow rate, although it may not even be possible to achieve optimal diffusion even if there is a lot of time allocated for the grouting operation.