The identification of natural frequency of machinery is a very important phase during the design, fabrication and testing process of any mechanical systems. This paper represents the experimental methodology for quick determining of natural frequency of a system by means of impact test. In this test, two kinds of sensors are used for the test, namely accelerometer and loadcell. The former is installed directly on the tested machine while the latter is built-in the hammer. Acquired signal from these sensors are analyzed and performed the Fast Fourier Transform (FFT) algorithm to get the transfer function. Then the natural frequencies of the system can be estimated. Besides, the corresponding coherences are also evaluated in order to evaluate accuracy of the results. This methodology is quite simple, less time consuming and very reliable for the natural frequency calculation.