The hydrogen evolution and IR absorption spectroscopy experiments are used to investi-gate the content and configuration of hydrogen in the amorphous carbon films(a-C:H).The results show that: with ilacreasing of the substrate temperature Ts, 1)the configuration of hydrogen in a-C:H changes from a two-phase structure to a single phase structure;2)the hydrogen content in a-C:H decreases monotonically;3)the ratio of sp3 bonds tO sp2 bonds ina-C:H increases monotonically.