Abstract: The grouting technology is applied widely in geotechnical engineering. However, due to grouting work belonging to concealment and underground construction,the research of the grouting theory and quality inspection is difficult and has no breakthrough progress as yet. The grouting inspection is a key to ensure grouting quality and to improve grouting technology. In order to improve the precision and reliability of inspection, the technology of ultrasonic inspection and the Expert System are combined and applied in grouting quality inspection in this paper. And the Expert System of grouting quality inspection is also detailed. According to the laboratory test and the spot inspection, the Expert System of grouting quality ultrasonic inspection is proved.