The interpretation of the pressure data of naturally fractured reservoirs (NFRs) has particular significance. The most famous theory for analyzing the pressure data of NFRs is the dual-porosity model presented by Warren and Root. Recent studies have shown that the dual-porosity model may not be appropriate for interpreting well test from all NFRs because this model has limits. In this study, the pressure Transient response of naturally fractured reservoirs was investigated by using numerical simulation without considering analytical and semi-analytical methods. To this end, a set of models including connected and disconnected fracture networks was simulated in the numerical simulator. The Warren and Root well-testing signature was observed in all simulations but it was highly evident for a well was located in the matrix and was negligible for a well that was intersected by fractures. The results of the simulation for the well that was intersected by fractures showed the bilinear flow regime with the slope of 1/4. The period of this flow regime increased in the unconnected fracture network and changed to the linear flow regime with a slope of 1/2 in two cases: firstly, by increasing fracture permeability in the connected fracture network, secondly, in the small-unconnected fractures. Moreover, the sensitivity analysis was performed on the well location in the connected fracture network. This research showed that by decreasing the distance between well and fracture network, the transition period becomes deeper and appears earlier.