An object of the present invention is to develop and provide a lung cancer differential marker with which lung cancer can be diagnosed conveniently and highly sensitively without depending only on increase or decrease in protein expression level between cancer patients and healthy persons. Another object of the present invention is to develop and provide a glycan marker capable of distinguishing histological types of lung cancer. Of serum glycoproteins, glycopeptide and glycoprotein groups whose glycan structures were altered specifically in lung cancer cell culture supernatants were identified, and they are provided as lung cancer differential markers.