Formal methods (FM) are mathematically based techniques that provide a rigorous basis for software development: the application of FMs makes it possible to achieve provable correctness and reliability in the various steps of system design and implementation. Generally, Formal methods need the support of formal description technique (FDT). Because the FDL has strict syntax and semantics. It is the realization of the abstract to the concrete, strictly, can be symbolic execution, unambiguous. E-LOTOS formal description is an important technology. This paper describes the design and the implement of the editor that support syntax highlighting of E-LOTOS. The editor is implemented using java Swing and JFlex.