C-70 crystals with size up to 3 x 3 x 0.2 mm were grown from benzene solution. The real and imaginary parts of the complex conductivity of this crystals were studied in the frequency range 20 Hz-1 MHz and the temperature range from 10 K to the room temperature. The temperature dependence of the real and imaginary parts of conductivity showed two frequency-independent anomalies at 150 and 275 K. These anomalies are interpreted as phase transitions.