Two Pt modified NiCoCrAlY coatings were prepared with the Pt-rich zone located at the coating surface (NiCoCrAlY + Pt) or at the substrate/coating interface (Pt + NiCoCrAlY). The microstructures of two coatings were studied with TEM. The hot corrosion performance of the coatings was investigated in Na2SO4/NaCl (75:25, wt./wt.) mixed salt at 900 degrees C in comparison with the plain NiCoCrAlY coating. The results revealed that the NiCoCrAl + Pt coating showed superior hot corrosion resistance due to higher Al content at the surface and merits of Pt in improving oxide scale adhesion. Ta was constrained beneath the coating/substrate interface in Pt + NiCoCrAlY coating owing to the strong affinity between Pt and Ta.