Abstarct: The process of artificially increasing porosity in low porosity formations increases the flow of fluid and increases the extraction of hydrocarbon resources. Hydraulic fracturing is known as a process of initiation and expansion of fractures due to fluid injection into a part of the well drilled in the formation. Many parameters affect the hydraulic fracturing test, such as the amount of stress applied, the rate of fluid injection, the viscosity, fluid pressure, and the tensile strength of the rocks. The purpose of this study was to investigate the effects of parameters such as viscosity, injection rate and fluid pressure on the hydraulic fracturing test. In this regard, the effect of the mentioned parameters on the samples of reservoir rock, cement, Sample of outcrops (limestone, tuff, sandstone and granite samples) was investigated. After lithological studies and determination of petrophysical parameters and rock mechanics of these samples, many hydraulic fracture tests were performed on the samples. In these experiments, the specimens were subjected to different axial and lateral stress conditions and then by injecting various fluids (water, oil, bentonite, guar gum, and xanthan gum) into the borehole drilled in the center of the specimen, at different injection rates, the hydraulic fracture pressure was obtained. The results show that with increasing viscosity and fluid injection rate, fracture pressure and injected fluid pressure also increase. As the viscosity decreases and fluid injection rates increase, the number of fractures increases. In the hydraulic fracture test, the tensile strength of the specimens was calculated and compared with the tensile strength obtained by the Brazilian method. Injection rate and fluid viscosity are the main factors in increasing the tensile strength of specimens in the hydraulic fracturing method. As the confining stress increases, the fracture strain-to-lateral stress ratio decreases. The results are also in good agreement with the lithological, petrophysical and rock mechanics studies of the samples.