The objective of this research is to use the variations of ultrasonic pulse velocity of concrete under compression as an indicator to determine the level of damage in concrete. Concrete used in this study consists of plain concrete and fiber reinforced concrete (FRC) at 0.5 and 1.0% volume fractions. Three types of fiber are used, steel, polypropylene and polyethylene. The strength of concrete is set at about 40 MPa at the age of 28 days. During the test, the specimens in form of 150x150x150 mm-cube are subjected to compression loading and at the same time, the ultrasonic pulse is transmitted through the concrete and recorded. The results indicate that the decrease in the ultrasonic pulse velocity of both plain and fiber reinforced concrete begins at the load level of about 30 – 40 % of the peak load. After that the decrease become faster, though at different rate (depending on the type of concrete). The rate of decrease appears to be lower in FRC than that of plain concrete. In addition, the variations of the ultrasonic pulse velocity are used to determine the damage level of concrete using the theory of damage mechanic. Results also show that at the similar level of loading, FRC exhibits less damage than that of plain concrete.