The invention discloses a material structure of a GaN-base enhancement-mode electronic device, and relates to the technical field of application of GaN-base power electronics and microwave power amplifiers. The material structure comprises a substrate, a GaN buffer layer and an Al(In,Ga)N barrier layer which are sequentially formed on the substrate, and a passivation layer, wherein the Al(In,Ga)N barrier layer forms a thin barrier Al(In,Ga)N/GaN heterostructure; and the passivation layer is formed on the thin barrier Al(In,Ga)N layer, and prepared from n-GaN, SiO2 or SiNx. Therefore, an enhancement-mode gate structure can be formed without etching the Al(In,Ga)N barrier layer; the density of two-dimensional electron gas in a thin barrier Al(In,Ga)N/GaN heterojunction channel outside a gate is significantly improved by utilizing polarization of the passivation layer or an n-type doping effect; the GaN-base enhancement-mode power electronic device with good threshold uniformity and low dynamic on resistance can be prepared; a yield of the device is increased; and an industrialization progress of the GaN-base power electronic device is pushed.