A piezoelectric dispenser having a uniform dispensing quality of a viscous liquid by calibrating an operation stroke of a valve rod discharging a viscous liquid (vertical operation displacement of the valve rod) by setting the operation stroke of the valve rod to an initial value during use, and a method of calibrating the operation stroke of the piezoelectric dispenser. Accordingly, a uniform dispensing accuracy of viscous liquid may be maintained, and degradation of the dispensing quality of a viscous liquid due to abrasion of components may be reduced.