Abstract: This paper summarized the diseases and syndrome differentiation of the spleen diseases in traditional Chinese medicine (TCM)， including the concept of the spleen， the etiology and pathogenesis， key points of syndromes and symptoms differentiation， therapeutic methods， prescription， and clinical application. The etiology and pathogenesis of spleen diseases could be categorized as excess and deficiency， which were represented as excessive dampness and weak yang， as well as dampness encumbering the spleen for the former， while spleen failure to remove dampness， weak yang and excessive dampness for the later. The syndrome differentiation was based on qi， blood， deficiency， excess， cold， and heat. The therapeutic principle was focused on transporting rather than tonifying. Such clinical manifestations were common as stomachache， abdominal pain， vomiting， hiccup， dysphagia， regurgitation， diarrhea， constipation， hematemesis， hemafecia， phlegm retention， and the spleen-warm syndrome. The therapeutic methods could be to warm the center and dry dampness， clear heat and remove dampness， expel water by purgation， supplement the center and boost qi， fortify the spleen and activate the center， boost the stomach and tonify yin， fortify the spleen and warm the center， as well as dissolve stasis and unblock the collaterals. The combined methods were like fortifying the spleen and soothing the liver， fortifying the spleen and harmonizing the stomach， soothing the liver and harmonizing the stomach， inhibiting the liver and reinforcing the spleen together with banking up earth to generate metal. As for the significant points of clinical application， it contains the common deficiency， excess， cold and heat combined syndrome， removing dampness to regulating the spleen， harmonizing qi to treat the stomach， tonifying yin to clearing stomach heat， along with focusing on the relation between the spleen， stomach， and other Zang-organs.