This article summarized the clinical experience of MEI Guoqiang in treating lung cancer of phlegm-heat obstructed in the lung syndrome with modified Xiaoxianxiong Decoction （小陷胸汤）. It is believed that the key pathogenesis of lung cancer with phlegm-heat obstructed in the lung syndrome is the phlegm-heat toxin accumulation. According to the different pathogenic effects of qi stagnation， blood stasis， pathogenic toxin， phlegm-damp， qi deficiency， yin deficiency in the occurrence and development of the disease， it is advocated to clear heat and resolve phlegm， and additionally the methods of diffusing the lung and relieving cough， resolving toxins and dissipating masses， rectifying qi and activating blood， dispelling dampness， supplementing and boosting qi and yin are used if necessary. Multiple methods are used together and flexibly matched. In clinical practice， Xiaoxian-xiong Decoction with the function of clearing heat and relieving phlegm is recommended as the basic formula for further modification. For patients with mild lung symptoms， modified Xiaoxianxiong Decoction is commonly used， while for those with obvious symptoms， self-made Maxing Xianxiong Decoction（麻杏陷胸汤） in modifications is suggested. For patients with Shaoyang （少阳） diseases， modified Chaihu Xianxiong Decoction （柴胡陷胸汤） is often used.