A design concept for suppressing the leading edge separation and tip leakage flow is introduced in order to improve aerodynamic performance of a transonic centrifugal compressor. The aerodynamic design method used in the present study is an inverse design method based on a meridional viscous flow analysis. As the design concept, the blade loading distributions at the leading edge are reduced to decrease the incidence angles. In addition, the peak of the blade load at the mid-chord of the full blade causes the second tip leakage vortex and tip leakage flow at mid-chord. On the other hand, tip leakage flow around the trailing edge is suppressed and aerodynamic performance is improved. The effectiveness of the design concept was evaluated by three-dimensional Reynolds Averaged Navier-Stokes simulations. The performance improvement was observed in the redesigned impeller compared with the conventional design impeller.