**Abstract**

Stress state in thermal barrier coatings (TBCs) has an influence on the service property and safety of coatings. The stress in TBCs should be characterized and measured. This is helpful for the guidance of design and preparation, the study of failure mechanism and the promotion of application of TBCs. This chapter reviewed the research progress on the stress measurement for air plasma spray (APS)-prepared TBCs. The origin and category of stress during preparation process and service were discussed. Then, the measurement technology and characterization method for stress in APS-prepared TBCs were focused. The common stress measurement techniques such as X-ray diffraction, neutron diffraction, Raman spectroscopy, photoluminescence piezospectroscopy, curvature measurement, material removal and indentation method were detailed. Furthermore, some suggestions were presented for the future work by summarizing the shortcomings of the exiting research.

**Keywords:** air plasma spray process, thermal barrier coatings, stress testing, stress analysis
