Abstract: This is t he author’s third in a series of articles discussing on t he system of interest bearing silver in t he Qing dynasty.Incorporating prior research t hat was mainly based on official Qing documents , t he aut hor compares t he system under Emperors Kangxi and Yongzheng.This article explores the both the rationale behind and content of the reform the system of interest bearing silver during the Yongzheng period and its basic policy and practice in the armies of Eight Banners and Green Standards.