By reviewing the ancient and modern literature, combined with the author’s own clinical experience, the author summed up and put forward the experience and thinking from the direction of different levels about exterior and interior. The tongue diagnosis can be divided into two parts: the texture and coating of the tongue examination. The tongue texture has close relation with Ying and Xue Fen, and the tougue coating has close relation with Wei and Qi Fen of human body. From the tongue color, shape and other aspects we can identify the situation of patients at Ying and Xue, and from the tongue coating’s exist or not, thiness or thickness, oiliness or greasiness, wetness or dryness etc, we can judge the situation of Wei and Qi. Clinically, if correctly analysing the tongue manifestation, judging the different conditions from which reflect Xue and Qi, and getting the judgment of disease and syndrome of patients, we can make accurate judgment on the patient’s condition, so as to correct further treatment and lay a solid foundation and strong guarantee for obtaining good therapeutic effect.