By combining the advantages of eddy current pulse excitation and infrared thermography, eddy current pulsed thermography (ECPT) has been used for testing and evaluating defects of key components in many areas. This paper focuses on using ECPT to test rolling contact fatigue (RCF) cracks and quantify their surface lengths. Due to the complex surface shapes of RCF cracks, a crack shape extraction procedure is designed which mainly includes crack response extraction and crack identification. Fitting parameters are utilized to evaluate the performances of four methods used in the crack response extraction step. Experimental results show that PCA-based thermal pattern in the early heating stage has the best performance for surface length quantification with its R 2 , sensitivity, and 2-norm of residuals of 92. 8%, 5. 91, and 2. 24, respectively.