Assesment of impact of climate change on water resources in river basin requires a proper estimation of availability of water and that can be achieved by hydrological modelling of the basin. The primary objective of this study is to develop a hydrological model to conduct a satisfactory rainfall-runoff study of Gumti river basin of Tripura, India. Besides this the physical characteristics of the river basin has been also determined. In this study a catchment simulation model Hydrological Modeling System, developed by Hydrological Engineering Centre, USA (HEC HMS) with soil moisture accounting algorithm has been calibrated and validated for Gumti river basin in North Eastern India for prediction of its hydrological response. The daily rainfall data and daily observed flow data of the two years 2012 and 2014 were used in developing the model. The catchment area has been divided into the 25 numbers of sub basins for detailed study. The rainfall in a particular rain gauge is considered as uniformly distributed over the entire sub catchments. Spatially distributed catchment characteristics have been obtained from the 90 m resolution SRTM digital elevation data. For computation of overland flows, the Soil Conservation Service’s (SCS) Curve Number (CN) method is applied in association with hydrometeorological properties, namely, soil type, land use, antecedent soil water conditions, and channel information. The simulated models by SCS method and Snyder’s UH are tested for two severe storms occurred over the catchment. The simulated results are found to match well with the observed value. The Nash – Sutcliffe model efficiency ranges from 0.61 to 0.911and the root mean square error 4.42% to 5.10% which indicates good performance of the model. Validation for the month of July 2014 was done by using two different transform and loss method to compare the results of simulation run. It showed that the second method which used SCS – CN loss method and SCS Unit hydrograph transform method produced higher peak values and also higher total monthly simulated flow values than the first method that used Snyder’s Unit hydrograph transform method at the outlet gauge Sonamura. Thus the study shows that the calibrated model performs well in simulating stream flow and that the model can be used for hydrological studies and water resource management of the Gumti river basin.