TreeBank is a crucial resource for syntactic parsing. But syntactic labeling and error checking for treebank is time and energy consuming. To improve the efficiency in constructing treebanks, we have designed and realized a treebank editing system based on a graphical interface. And this graphical treebank editing system is proved to be 5 times faster than error checking on bracket marked syntactic treebank. As such it provides a technical support for building a large-scale syntactically annotated corpus.