The objective of the develop a database system project to support indicators of the rational use of drugs is to develop a database structure for answering various indicators related to the rational use of drugs at all levels. In this project, three parts were done: 1) development of a tool for calculating the indicators of rational use in hospitals; by relying on a database in the hospital information system. This is a new version of ThaiRDU with 3 platforms: a) HOSxP with MySQL database management b) HOSxP with PostgreSQL database management and c) Hospital OS can process 18 indicators for rational drug use in hospitals. All 3 platforms covered almost all the use of hospital information systems of the Ministry of Public Health. ThaiRDU tool was developed with the Delphi program and installed into the Windows operating system. The program was easy to use and no structural changes were made in the database of the hospital information system. It could be processed anytime online. A list of drugs used in hospitals could be set for calculating the indicators. Using hospital drug codes and not relying on 24-digit drug codes, the list of drugs that was imported into processing was accurate. In some indicators, the use of ThaiRDU might be a factor in obtaining indicator values that differed from those reported on the HDC website. 2) The results of the several indicators in three fiscal years obtained from the three data sources, i.e., the developed tools (ThaiRDU), the HDC website (HDC Service), and the Big Data on HDC (HDC Big Data) were similar. However, the results of some indicators were different which depends on many factors. One of those factors was transferring the correct information from the hospital into the HDC system in a timely manner. Using ThaiRDU has the advantage of being able to use primary sources directly. The relevant drug list can be defined without the need for a 24-digit drug code, and the drug list can be updated to be correct at any time. In the case that the hospital has already sent relatively accurate information to the system, the website provides a service plan processing service related to rational drug use that will process various indicators correctly. According to the policy, the hospital will have time to adjust the correctness to bring it into the processing at a certain time. Therefore, the reported values through this HDC website will not change. Researchers can use data from Big Data to process tasks of rational drug use, and 3) define a standard structure for rational drug use. Because the utilization of the accumulated information will be in the form of data analysis, the research team chose a design in terms of fact constellation, i.e., more than one fact table. In this research, two fact tables in two main modules were designed, i.e., the prescription_fact and literacy_fact were fact tables in a module of prescription which was used for analyzing drug use of patients, and a module of health literacy which was used for analyzing health literacy of people, respectively. In the rational use of a drug monitoring system, it can be seen that there is a need for a systematic database to process various indicators. The most systematic database that measures people's actual drug use is the HDC. It focused on drug use in hospitals in the Ministry of Health. This should be proposed to expand to all health services. It is important to measure health literacy. There is still a lack of a database that collects matters related to health literacy at the levels of health media, activities, and various questions used to measure health knowledge. The agencies responsible for such databases in the development of the database are therefore important parts of the further development of rational drug use at all levels.