Single InAs quantum dot (QD) sample is grown by molecular-beam epitaxy (MBE), and the photoluminescence (PL) from a single QD at 5 K is measured. By means of Hanbury-Brown and Twiss (HBT) setup, we measure the photon correlation of the PL which indicates that the PL of QD is single-photon emission. This single-photon source is used to demonstrate experimentally the single-photon interference via Mach-Zehnder (MZ) interferometer. In addition, the measured interference and fringe visibility are analyzed by changing the different linear polarization of the photon between two arms of MZ interferometer.