Objective　To analyze and evaluate the joint teaching of subspecialty teachers in the application of diagnostics probation. Methods　293 clinical medical undergraduates of Grade 2009 were randomly divided into experimental group（the joint subspecialties teaching group， n=153） and control group（traditional teaching group， n=140）. The two groups of students were divided into the 14-16 study group. The diagnostics probation teaching content（all general physical examination and ECG examination）was decomposed in the experiment group and students were taught by different sub-specialties teachers while the students of the control group were taught by a teacher of internal medicine. The final examination grades and operative performance of the two groups were compared， evaluated and U tested. At the same time the questionnaire survey was conducted to the students in the experimental group. Results　The experimental group's theory examination score was （75.2±8.9） and the operative assessment score was （88.5±6.2）， higher than that in the control group（70.9±10.7 and 84.6±5.5）， the difference was statistically significant（P=0.001）. The questionnaire results showed 92.8%（142/153）medical students improved their clinical skill， 86.9%（133/153） medical students were satisfied with the joint teaching of subspecialty teachers. Conclusions　The subspecialty teachers' joint teaching can improve students' clinical practice ability. It is a valuable teaching method in diagnostics teaching.