Abstract: The problem of symmetric elastic contact between an axially gradient Timoshenko beam of Gaussian-function type and a rigid circular indenter was studied in this paper. By expressing the deflection, rotation angle, bending moment, and shearing force of the beam in term of confluent hypergeometric series, the parametric equation of the indentation force-depth curve with the contact radius as the parameter was derived analytically. The analytical linear approximation for the starting part of the curve was further obtained by using Taylor expansion, and it was found that the linear approximation is exactly the solution for the mid-span deflection of the beam under a concentrated force acting also at the mid-span. An empirical formula for the approximate length of the linear starting part of the curve was given through the ergodic parametric analysis, and the influence of the axial gradient factor and the beam length on the slope of the linear starting part (i.e. the initial contact stiffness of the system) was investigated. The results show that, for a given beam length, the axial gradient factor has a positively correlated one-to-one correspondence with the slope of the linear starting part of the indentation force-depth curve. This conclusion is of certain theoretical value for the high-throughput characterization of axially gradient samples via indentation.