Abstract: InN thin films are grown on GaN/sapphire substrate by metalorganic chemical vapor deposition.The electrical and optical properties of the InN films are investigated by means of Hall，absorption spectra and low-perature (10K) photoluminescence (PL) measurements. It is shown that the carrier concentration ranges from 10^18 to 10^19cm-3.The bsorption spectra , low-temperature PL measurements and PL peak shape analyses indicate that the band gap of InN is about 0.7eV. From the results of Hall，absorption spectra and PL measurements an obvious blue-shift of the absorption edge and PL peak energy is observed with increasing the carrier concentration.In addition，the uncertainty of the InN band gap making an inference from absorption spectra is discussed.

Key words: InN, metalorganic chemical vapor deposition, Hall, absorption spectra, photoluminescence