In this letter, an avalanche photodiode (APD) for ultraviolet detection was fabricated on a 4H-SiC epi-layer with a radius of 150 µm. By adopting passive quenching method, the impact of quenching resistor on single photon detection performance of the fabricated APD was investigated for the first time. It is found that both dark count rate (DCR) and single photon detect efficiency (SPDE) were reduced with the increasing quenching resistance. When the DCR fixed at 5 Hz/μm2 , the SPDE is 7.1% /6.7%/5.4%/5.2% corresponding to the quenching resistance of 10/20/50/100 kΩ. Variation of the SPDEs can be ascribed to the changing death time by comparing the photon counting spectra with various resistors. The obtained results have built up a good basis for the design of SiC APD single photon detection.