This paper provides explanations and analysis of how the power coefficient (Cp) of the Parabolic wind rotor has been affected by changing its geometrical design parameters. The results were presented in the form of (Cp) curves as a function of tip speed ratio (lambda(0)). The aerodynamic mathematical mode called "multi-streamtube" was implemented. To determine the Cp(lambda(0)) of the Parabolic rotor, regardless of its engineering shape, a computer program has been prepared by using Microsoft Visual Basic. The geometrical design parameters covered in this study are rotor blades number (N), rotor height (h) or (2H), rotor diameter (2R) and chord line (C). Whereas, through these parameters a total of 57 configurations were utilized and adopted. Thus, this number of different designs was sufficient to identify the performance behaviors of the Parabolic wind rotor. Accordingly, the results indicated that increasing rotor height to diameter ratio (H/R) leads to a decrease in Cp over low tip speed ratio range for all values of solidity, sigma, (NC/R) investigated. However, higher values of (H/R) result in a raise in Cp over high tip speed ratio range for values of (NC/R) less than 0.2 approximately. Thus, it seems that higher (H/R) values constitute an advantage for fast rotating rotors (low (NC/R) and high tip speed ratio).