This study, which analyzes the measures put in place by Sirhak scholars to curb corruption during the latter period of Choson, focuses on the 〈Mongmin sims? (牧民心書, A Book From the Heart on Governing the People)〉 written by Ch?ng Yakyong. First, the 〈Mongmin sims?〉 did not advocate the reform of the existing system but the improvement of the management of local administrative affairs by appealing to the conscience of local governors and magistrates. Second, this book was based on the knowledge the writer acquired during his youth from his father with regards to governance, his own experience as local governor, and the results of his studies on the Confucius Classics, sas? (四書, the Four Books of Ancient China; the Analects of Confucius, the Works of Mencius, the Doctrine of the Mean, and the Great Learning), and the mongminso (牧民書, books about governing people). Third, Ch?ng asserted that in order to curb corruption and improve the management of local administrative affairs, local governors and magistrates would have to abide by strict moral regulations. Ch?ng also claimed that governors and magistrates would have to purify their surroundings if corruption was to be eradicated. Fourth, he also asserted that integrity alone would not be enough to stem corruption; in that, local governors and magistrates should also possess in-depth experience with, and knowledge of, the management system. In this regards, Ch?ng stated that the mere possession of integrity did not automatically bestow upon one the ability to resolve actual problems. Rather, such a situation would only lead to an increase in the power of the s?ri (clerk) class. Fifth, on the subject of the ch?nse (田稅, land tax), kuny?kse (軍役稅, military corvee labor tax), and hwangokse (還穀稅, grain tax), Ch?ng Yakyong was of the opinion that management methods should be improved in order to prevent corruption and decrease the burden on the public. Here, Chong advocated the implementation of such principles as the development of an equalized taxation system and the prevention of exploitation on the part of the aj?n class. Moreover, these objectives should be secured through such means as assessing taxes on lands and social classes that had heretofore been exempted. Sixth, as far as the improvement of the samj?ng (三政) system was concerned, Ch?ng believed that each local governor and magistrate should carry out their reform duties in accordance with the reality on the ground and their own personal situation. He was of the mindset that undesirable effects might emerge should a local magistrate chose to impose such improvement measures too strictly. Seventh, in terms of the chapy?kse (雜役稅, miscellaneous labor tax), Ch?ng called for local magistrates, under whose jurisdiction this tax fell, to establish reasonable institutions that were based on the application of the principles of equalized taxation in order to reduce the public burden. Eighth, Ch?ngs idea of establishing a kongj?n (公田, public land) system to collect the chapy?kse was closely linked to the reform measures for the ch?ngj?n (井田, regular field) system which he first introduced in his 〈Ky?ngse yup´yo (經世遺表)〉. As such, although these two books advocated different sets of reform measures, the 〈Mongmin sims?〉 and 〈Ky?ngse yup´yo〉 can be regarded as being closely related to one other. Ninth, Ch?ng also claimed in the 〈Mongmin sims?〉 that local magistrates should directly oversee, inspect, and control important administrative affairs. Tenth, Ch?ng asserted that in order to improve the taxation system local governors and magistrates should treat the aj?n class, who were actually carrying out the local administrative affairs, with a mixture of generosity and sternness. Moreover, Ch?ng Yakyong's governance theory was closely related to his thoughts on scholarly pursuits. He thought that such pursuits should not consist solely of educating oneself (susin 修身), but should be extended to the application of this knowledge to the actual governing of the public (chimin 治民 ). Here chimin can be understood to refer to the mongmin. As such, the mere cultivation of oneself represents studies which have only been half-completed. In other words, Ch?ng believed that scholars should apply their knowledge to the actual improvement of politics and administrative affairs.