This paper examined the ability of √area△ using the material fatigue-life curves in estimating high-cycle fatigue life considering micro scratch. Ultrasonic fatigue tensile experiment were reported in determining the fatigue life model for micro scratches, where fatigue failure of all the specimens occurred from surface in the lab study. A high cycle fatigue (HCF) life model of TC17 based on micro scratches is established with the synthesis of surface condition fatigue strength modified by √area△ and the three-parameter power function. Reasonable agreements are observed between the model predictions and the experimental values. What is more, according to the application of √area△ from current papers, it can be suggested that the proposed √area△ is suitable for being used in fatigue strength and fatigue life analysis.