Abstract:Jackson System Development method, JSD, is a famous operational software development approach in the 80 s. We designed a JSD-based graphical operational specification language-NUJSDL and a supporting systemNUJSDS which supports the use of the method in the practice of software development. NDJSDL has the characteristics of understandable, analysable and maintainable etc. The results of the different phases in JSD development procedures are described by the various mechanisms in NUJSDL separately. A specification and the transformation from specification to software procedural description.