Friction is one of the fundamental issues in physics, mechanics and material science with many practical applications. However, the understanding of macroscopic friction phenomena from microscopic aspect is still on the way. In this paper, molecular dynamics simulations are performed to investigate the static friction between two planar crystal surfaces. The friction force experienced by each atom is tracked and the statistical characteristics of atomic friction force are illuminated. More importantly, the influences of normal load and temperature on the statistical features are generalized. This study provides a new insight on the micro-states of friction.