This article discusses the history and development of commercial law in Indonesia and its correlation with the civil code law. This article uses literature research. Commercial law is the law that regulates the behavior of humans who participate in trading for profit or the law that regulates legal relations between humans and legal entities with each other in the trading field. Generally, the development of commercial law is divided into three stages, namely the lex mercatoria period in the Middle Ages, the incorporation of the lex mercatoria into the national legal system, and the new lex mercotaria period. In essence, lex mercotaria is a concept in Latin that is used to communicate a set of principles or principles that apply to traders in Europe in general. When viewed from the perspective of its function, lex mercotaria is actually an international trade law which, among other things, emphasizes the separation of assets and contractual freedom, applies to traders from various parts of the world who establish trade relations with the citizens of the kingdom along the route that crosses the boundaries of territorial sovereignty. . based on the principle of concordance, the KUHD Netherland 1838 became an example for the making of the Indonesian KUHD in 1848. Initially, commercial law was based on civil law. However, over time the commercial law codified the legal rules so that the Commercial Law Code was created which is now independent or can be said to be separate from the Civil Law Code. The Commercial Law Code has a relationship with the Civil Law Code as explained above that as a result of the codification, commercial law is part or a branch of civil law, but in a more specific form. Thus, the Civil Code becomes a special source of civil law. The relationship between the two laws is the genus (general) and species (special).