In this paper, two different surface treatments for bulk HgCdTe are compared in the point of surface recombination velocity and diode dynamic resistance-voltage characteristics. One surface treatment, named as standard treatment, is only Br-MeOH etching and the other, named as nitric acid (HNO3) treatment, is composed of chemical oxidation with nitric acid after Br-MeOH etching and the removal of the oxide with ammonium hydroxide. After such surface treatments, gate- controlled diodes were fabricated and surface recombination velocity were measured to be 170 cm/s and 70 cm/s for the standard treatment and nitric acid treatment, respectively. And, the nitric acid treatment diode satisfied BLIP dynamic resistance characteristics regardless of the variation of the gate voltage. Moreover, from the measurement of capacitance- voltage characteristics, it was found that nitric acid treatment reduced the hysteresis width in the C-V curves of ZnS/HgCdTe MIS capacitor by one tenth compared to standard treatment. It is thought that the nitric acid treatment reduces surface-related defect and charge.