This research was conducted to find out how the implementation of Proprietary and entity theory in chemical companies. This research is a quantitative research with a descriptive method which provides an overview regarding the implementation of the Proprietary and entity theory, to find out the impact and interrelationships of this theory on financial performance or its impact on the company. This research was conducted by collecting various literature related to the topic under study, which was sourced from libraries and the internet and financial reports from chemical companies which became a reference source in determining the description of the implementation of the Proprietary and entity theory. Based on the findings of this study, through the observed data, it was found that the application of the Proprietary Theory was still not optimal, which was illustrated by the DAR value of chemical companies that were still under the less good category, namely below 30%, it could be concluded that the Proprietary Theory that in a sense it will help the company to optimize the optimal ownership structure for the company. Then through the DER data that has been collected by researchers it is found that the value of the DER ratio of chemical companies is in a good category, which is above 90%, this indicates that entity theory has been optimally implemented by chemical companies, in which entity theory is able to help companies create entity structures. through DER optimally to the company