Objective: The aging model of guinea pigs induced by D-galactose was set up to investigate the changes of BK_Ca expression and function on cochlear pericytes and their relationship with age-related hearing loss. Methods: Thirty healthy 8-week-old guinea pigs were randomly divided into three groups, with 10 in each group: D-galactose aging model group, subcutaneous injection of D-galactose (500 mg/kg) daily for 6 weeks; saline control group, the same amount of saline was injected into the neck of the aging model group for 6 weeks; the blank control group, no treatment was performed. The threshold of auditory brainstem response (ABR) was detected. The content of BK_Ca in the perivascular cells of the guinea pig cochlear cells was detected by immunofluorescence technique. The changes of peripheral current density and BK_Ca current were detected by patch clamp technique. The data were analyzed by GraphPad Prism software. Results: Compared with the saline group and the control group, the ABR threshold and the amplitude of the wave I were significantly decreased in the aging model group, and the difference was statistically significant (P<0.01). Compared with the control group, the expression of BK_Ca in the vascular pericytes of guinea pigs in the aging model group was significantly reduced (1.00±0.08 vs 0.27±0.03,the difference was statistically significant P<0.01), and the cell current density and BK_Ca net current value were also significantly reduced with statistically significant (P<0.01). Conclusions D-galactose can successfully induce guinea pig aging model, in which BK_Ca expression decreases and net current value decreases in pericytes of cochlear striavascularis, and changes in BK_Ca expression and function may be related to age-related hearing loss.