This paper presents a procedure of single gear tooth analysis for early detection and diagnosis of gear faults. The objective of this procedure is to develop a method for more sensitive detection of the incipient faults and locating the faults in the gear. The main idea of the single gear tooth analysis is that the vibration signals collected with high sampling rate are divided into a number of segments with the same time interval. The number of the signal segments is equal to that of gear teeth. The analysis of individual segment reveals more sensitively the changes of the vibration signals in both time and frequency domain caused by gear faults. In addition

the location of failed tooth can be indicated in terms of the position of the segment that deviates from normal segments. A numerical simulated signal and an experimental investigation verified the advantages of the single gear tooth analysis.