This paper described one-step method to preparing supercapacitors by using natural ganoderma lucidum spores, whose hollow cage structure could facilitate the transmission and storage of electrons. We have investigated the effects of carbonized temperature and carbonized gas on the electrochemical properties of spores. After carbonizing the spore material under flowing ammonia, the nitrogen doping content of it was 8.86%. The specific capacitance of the prepared electrode was 187.3 F/g (at 1 A/g). After 10,000 charge-discharge cycles, the sample remained 93.3% of its capacity. In addition, after being irradiated by gamma ray (50 kGy), the carbonized sample remained 100.7 F/g (at 1 A/g) of specific capacitance.