Abstract: The idea that use the structure of semantic meaning query tree as middle language is put forward.The algorithm of translation Chinese query sentence of GIS into semantic meaning query tree is designed.In order to solve the difficulty of nested structure of SQL,the idea of query block is introduced and the algorithm of changing query block to SQL is realized.The compare of this way with old ones has been done.The experiment shows that the validity has been enhanced.So it is a better way to understand Chinese query sentence.