Abstract Au disk targets were irradiated with -0.8 ns, 1.05 and 0.53 μm laser. The intensity and angular dependence of absorption were studied experimentally. The experimental results of absorption by laser-produced plasma are introduced in this paper. The measured absorption with plasma calorimeters accord with one-dimension planar simulation. The experiment and theory show that collision absorption is the main absorption mechanism. A scaling law of absorption has been suggested based on the careful analysis of the experimental results.