Determination of mechanical properties with nanoindentation tests needs a knowledge of contact area, which is characterized with an area function. In the current methods, typically the Oliver-Pharr method, the area function is usually calibrated with the reference materials prior to practical tests. However, the accuracy and applicability of such a pre-calibrated area function have been questioned in many studies by considering the difference between the indentation response of the real test sample and that of the reference material. In order to overcome this problem, a simple method was proposed in the present study to calibrate area function and extract mechanical properties simultaneously with the same load-displacement curve. Due to theself-calibration, rather thanpre-calibration, nature of this new method, the resultant area function may accurately reflect the response of the test material to nanoindentation. Analyses of the nanoindentation data measured on several typical materials, including glass, metal and ceramic, confirmed that reasonable values of Young's modulus and hardness can be extracted with this new method.