In order to obtain characterization of coating material,the modulated pho tothermal radiometry (PTR) which is non-destructive and contactless is used.A one-dimensional photother mal radiometry model of a three-layered system is established to measure the thermophysical parameters, thickness and its distribution of coatings on aluminum substrates.The three layers are coating,air gap and subs trate,respectively.Measurement instrument is set up and three samples are tested,two of which are aluminum substrates with cobalt coatings with different thicknesses,and one is pure aluminum.Then multi-point detections are processed for each sample. The normalized PTR phase signals are obtained by the normalization procedure be tween the experimental samples and the reference sample,aiming at eliminating the influence of detectio n system.A multi-parameter fitting optimization algorithm is used to acquire t he thermal conductivity and diffusivity of the coating material.Then the thickness of each detected point and the thickness distribution of each experimental sample are obtained based on the previous work.The experimental results show that the theoretical model is reasonable,and it also confirms the conclusion that the values of the thermal co nductivity and diffusivity of the material as coating are much lower than those in literature.The thermophy sical properties of coating are typically different from those of bulk materials.