Although In2O3 nanofibers (NFs) are well-known candidates as active materials for next-generation, low-cost electronics, these NF based devices still suffer from high leakage current, insufficient on-off current ratios (I-on/I-off), and large, negative threshold voltages (V-TH), leading to poor device performance, parasitic energy consumption, and rather complicated circuit design. Here, instead of the conventional surface modification of In2O3 NFs, we present a one-step electrospinning process (i.e., without hot-press) to obtain controllable Mg-doped In2O3 NF networks to achieve high-performance enhancement-mode thin-film transistors (TFTs). By simply adjusting the Mg doping concentration, the device performance can be manipulated precisely. For the optimal doping concentration of 2 mol%, the devices exhibit a small V-TH (3.2 V), high saturation current (1.1 x 10(-4) A), large on/off current ratio (> 10(8)), and respectable peak carrier mobility (2.04 cm(2)/(V.s)), corresponding to one of the best device performances among all 1D metal-oxide NFs based devices reported so far. When high-kappa HfOx thin films are employed as the gate dielectric, their electron mobility and V-TH can be further improved to 5.30 cm(2)/(V.s) and 0.9 V, respectively, which demonstrates the promising prospect of these Mg-doped In2O3 NF networks for high-performance, large-scale, and low-power electronics.