Two-dimensional (2D) transition-metal dichalcogenide semiconductor (TMD), MoS2 has received extensive attention for decades due to their outstanding electrical and mechanical properties for next generation devices. One weakness of MoS2, however, is that it only shows n-type conduction revealing its limitations for homogeneous PN diodes and complementary inverters. Here, we introduce a charge-transfer method to modify the conduction property of MoS2 from n- to p-type. We initially deposited n-type InGaZnO (IGZO) film on top of MoS2 flake, so that electron charges might be transferred from MoS2 to IGZO during air ambient annealing. As a result, electron charges were depleted in MoS2. Such charge depletion lowered MoS2 Fermi level, which makes hole conduction favorable in MoS2 when optimum source/drain electrodes with high work-function are selected. Our IGZO-supported MoS2 flake field effect transistors (FETs) clearly display the channel type conversion from n- to p-channel in this way. Under short and long annealing conditions, n- and p-channel MoS2 FETs are achieved, respectively and low voltage complementary inverter is demonstrated using both channels in a single MoS2 flake.