This paper introduces a simple method for modeling and simulation of Surface acoustic wave (SAW) resonator using Computer aided design (CAD) tool. The model is built for 1-port SAW resonator. A lumped equivalent circuit model is used to extract the electric parameters of 434 MHz SAW resonator. A modified equivalent circuit is presented. SParameters are calculated mathematically and the model is simulated using a novel simulation tool (Octave). Voltage standing wave ratio (VSWR), impedance, and admittance and insertion loss are also predicted using S11 parameter. Smith chart of impedance determine the reflection coefficient in a polar form normalized to input matching impedance. The obtained results are compared with one commercial device which satisfies the simulationresults. Octave tool with the presented model performs quicksimulation with high performance and accurate results.