Shape memory alloys are known as intrinsic wear resistant materials. This research was devided in three main groups of subjects related to study of wear behaviour of these alloys. Thus, the wear behavior of superelastic nickel titanium (Nitinol) shape memory alloy was evaluated in different conditions such as normal loads, ambient temperatures, sliding distances, initial surface roughness, surface preheating and history of wearing process against a steel disk with the aim of extracting a thermomechanical wear model for shape memory alloys based on experimental results using pin-on-disk wear testing device. In the second group of studies, two mechanisms of two-body and three-body abrasive wear on the Nitinol shape memory alloy were examined. For the first time, this attempt focuses on this phenomenon in these alloys. In the third group, the first attempt of research was done to get acquainted with the relation of acoustic and wear in shape memory alloys. In the study of the wear behavior of Nitinol shape memory alloy, for the evaluation of indentation behaviour, micro and macro hardness devices using Vickers indetor, and nanoindentation device using Barkovich dentator were used. Oliver and Pharr method was used to evaluate the results of the indentation method. The tensile test device was also used to extract the required parameters of this alloy. A Stylus Profilometer and Atomic Force Microscopy were used to detect surface roughness of Nitinol wires. DIN 1.2080 cold work steel was used after thermal treatment to achieve the desired hardness for making the disc. To test the acoustic emission, a B K sound meter and Samsung cellphone were used. While investigating of Nitinol wear, it was observed that the hardness was roughly independent of indentation load. Hardness increased with increasing temperature. The friction coefficient of the stable state of wear was independent from the vertical wear load, initial roughness of the surface, history of wear, the preheating process, ambient temperature, and was approximately equal to 0.6. With increasing normal load, wear rate also increased, and as the temperature rised, the wear rate decreased. By transforming the three-body wear to the two-body wear which is available by removing the wear particles from wear path, the coefficient of friction, the wear rate and acoustic emmition dropped sharply, and the wear mechanism changed from severe to mild. The coefficient of friction in the two-body wear of Nitinol against the steel disk was between 0.1 and 0.3, while the coefficient of friction in the three-body wear related to the same materials was between 0.5 and 0.8. The visual effect of the two-body wear on the second body was much milder compared to the effect of the three-body wear on the second body. By the distance from the source of sound, the sound intensity and percentage of the predominant sound intensity increased. As the load increases, the intensity of the sound increases both in the two-body and the three-body wear. With increasing the load in two-body wear, percentage of the predominant sound intensity was declined. The three-body wear intensity had much more fluctuation. The frequency of the two-body wear was much higher than that of the three-body wear frequency and decreased by increasing in load. By providing presented thermomechanical wear model for shape memory alloys, it was possible to predict the wear behavior of these alloys at different temperatures and normal loads. On the other hand, the wear resistant behavior of these alloys can be doubled by changing the wearing conditions into two-body wear. Under these conditions, using the acoustic emission technique, it is possible to examine the wear conditions without stopping the system before reaching critical conditions. Keywords: Shape Memory Alloy, Nickel-Titanium, Nitinol, Tribology, Indentation, Wear, Friction, Acoustic emission