Microwave heating chemical vapor deposition (CVD) is used to deposit titanium diboride (TiB2) films on graphite substrate using a gas mixture of TiCl4, BCl3, H2 and Ar. The influences of microwave power and the growth rate of TiB2 are studied by using X-ray diffraction, field emission scanning electron microscopy (FESEM) and energy dispersive spectrometer (EDS). In the range of experimental conditions, the TiB2 film’s micro-hardness evaluated by using a computer controlled micro-hardness tester increases with increasing deposition temperature and microwave power. The grain size and the growth rate of TiB2 film are also improved with increasing microwave power at a fixed gas flow ratio of TiCl4 and BCl3, and the bulk TiB2 is obtained at a higher hardness.