In-depth application of the combination of theory and practice is one of the keys to improve the clinical undergraduate teaching quality of clinical laboratory diagnosis.Xuanwu Hospital used ISO15189 standards as a guide to make students fully participate in establishing performance verification and recording registration form,partly participate in the gage calibration,external quality assessment and inter-laboratory comparison etc.It also used the combined form of practice with teaching to make students learn the file writing and the equipment calibration.An orderly teaching model composed of knowledge reserve,file learning,calibration and verification was established,which was a closed-loop system that enabled students to become more deeply and extensively involved in the system and more deeply understand the connotation of clinical laboratory quality.