Message Sequence Charts (MSCs) have widely used in software engineering for sys- tem requirements and test speci‾cations. Since 2005, MSCs also have been adopted as the test speci‾cation of TTCN-3 (Test and Testing Control Notations). We have developed a user-friendly environment for the construction of MSC test speci‾cations. We have a parsing table that is a data structure storing information of MSCs. Our GUI (Graphical User Interface) reads the parsing table then shows symbols on the window. User can edit these symbols and save back to parsing table. This thesis re- ports the implementation technology of GUI supporting MSCs and TTCN-3 Graphical presentation format (GFT).