In this paper,we report on several experimental characterizations of a quasi-optical spiral antenna coupled NbN hot electron bolometer(HEB)mixer.This superconducting HEB mixer consists of an elliptical lens with a long axis of 10.456mm and a short axis of 10mm,a log spiral planar antenna(growth rate measuring 0.32 with an azimuth angular 11.2)and a 5.5-nm thick NbN thin-film microbridge with an area of 3 μm*0.3 μm.The designed frequency range is determined by the inner and outer diameter of spiral antenna and is from 0.1 THz to 1.5 THz.The measured double-sideband receiver noise temperatures of this superconducting HEB mixer are 800 K at 220 GHz,750 K at 330 GHz,900 K at 500 GHz,800 K at 850 GHz and 1500K at 1300 GHz.The deterioration of noise temperature at 1300GHz can be attributed to the insufficient LO power.The IF noise bandwidth of this mixer is 3.5 GHz and stays the same at 500 GHz and 850 GHz.Furthermore,the HEBs frequency response has been measured by a Martin-Puplett type Fourier transform spectrometer.FTS measurement demonstrates a high coupling efficiency in the frequency range of 0.1~1.6 THz.Detailed measurement results will be presented.