Abstract: ZrO2 thermal barrier ceramics coating was prepared by plasma spraying with nano ZrO2 powder as raw material and microstructure of the coating was observed. The results show that the coating was composed of fusing area and half fusing area. Many pores were observed in the coating with the shape of stripe and subsphere,but no perfoliate pores were found. There were some tiny cracks which had no obvious direction. In the coating,the particles grow up to different degree and some of them were separated from a nano level to a micro level.