The development of human life triggers the birth of various architectural styles. Architects often mix various styles in designing buildings. This mixed architectural style is known by the name of eclectic architecture. Previous research on eclectic architecture showed that one of the themes of eclecticism is the reuse of classical architectural style. This architectural style can be seen in one of the public buildings that accommodate an important function, namely the building of the Constitutional Court in Jakarta, Indonesia. This research aims to understand the eclectic architecture in general and traces the application of eclecticism specifically to the architectural design of the Constitutional Court building. The method used for this research is: firstly, describe all scope of the building. Secondly, confront the description of the building with the principle of Classic architecture design. The results of the analysis showed that the Constitutional Court building architecture does not fully applied the principle of Classical architecture, but merely embellished elements of Classical architecture on the elevation. This research will be very useful for the development of architectural theory. While in practice, the results of this research can be used as guidance for architectural practitioners using the eclectic approach. For laypeople, this research can be a new alternative to appreciate the work of architecture.