Abstract： The purpose of this paper is to introduce the clinical experience of modified Guizhi tang in treating external contraction and fever of children in summer in the Lingnan area. In clinical practice， it is found that most children in the Lingnan area have the constitution of spleen-stomach deficiency cold，and the external contraction and fever in summer is usually deficiency at the root and excess at the tip. As for the treatment， it is necessary to reinforce the healthy qi and eliminate the pathogenic factors and protect the spleen and stomach at the same time. Guizhi tang can release the exterior and harmonize the nutrient and defense，as well as fortify the spleen and reinforce the healthy qi，which comprehensively reflects Zhongjing's thought of protecting the spleen and stomach. What's more， modification of Guizhi tang based on syndrome differentiation can help fit the pathogenesis characteristics of external contraction and fever of children in summer in the Lingnan area，so it is effective in clinical application.