Boron carbide thin films have been synthesized via pulsed laser deposition process using Spark Plasma Sintered (SPSed) and dual-targets, respectively. Two kinds of structural evolutions have been found by investigation of bonding environments in as-deposited thin films via X-ray photoelectron spectroscopy study. With decreasing of B/C ratio, films deposited from SPSed-target show the transformation of B11C-CBB B11C-CBC. In contrast, the films deposited from dual-target present the B11C-CBB B10C2-CBB structural change.