Universal Mobile Telecommunications System (UMTS) is one of the standards in 3rd generation partnership project (3GPP). Different data rates are offered by UMTS for voice, video conference and other services. This thesis presents the performance of UMTS cellular network using sectorization for capacity and coverage. The major contribution is to see the impact of sectorization on capacity and cell coverage in 3G UMTS cellular network with independent dynamic parameters as energy per bit to noise spectral density ratio, soft handover factor, voice activity factor, intercell or outercell interference factor, data rates. Different parameters that influence the capacity and coverage of UMTS cellular network are simulated using MATLAB. In this paper, the outputs of simulation for increasing amount of sectorization with different parameter showed that the number of users gradually increased. The coverage area also gradually increased for particular data rates.