Mohammad alazemi¹, and  A. E. Badr^{2 1}Department of Conservative Dentistry and Endodontics, Faculty of Mansoura University, Mansoura, ²¹Department of Endodontics, Faculty of  Dentistry Mansoura University. Objectives: the purpose of this study was to compare the shaping ability of different NiTi rotary systems (WaveOne, WaveOne gold, Reciproc, Reciproc blue) in extracted human teeth using cone-beam tomography (CBCT) scanning. Methods : Sixty mesiobuccal canals of mandibular molars with angle of curvatures between 〖25〗^o-〖45〗^o degrees, were randomly divided into 4 experimental groups (n = 15), according to the NiTi rotary system used, WaveOne, WaveOne gold, Reciproc and Reciproc blue Canals were scanned before and after instrumentation by using CBCT scanner to evaluate canal transportation and centering ratio at 3, 6 and 9 mm from the apex. Data were statistically analyzed and the significance level was set at P < .05. Results: Reciproc blue and WaveOne gold showed significantly less canal transportation and more centering ability, compared to WaveOne gold and Reciproc systems. Conclusion: Within the limitation of this study, least canal transportation and high centering ability was produced by Reciproc blue and WaveOne gold systems with evenly dentin removal from canal walls better than WaveOne and Reciproc instruments