The present invention relates to a pharmaceutical composition for the decrease in airway allergic sensitization and inflammation. The composition comprises heparin of different molecular weight, including the heparin and enoxaparin. We found daily intranasal use of heparin or enoxaparin exerts a long term effect on airway allergic inflammation, especially bronchial asthma. In the mite-induced airway allergic inflammation in BALB/c model, the heparin and enoxaparin can decrease serum mite-specific IgE level, cytokines in lung protein extract, peribronchial and alveolar pathology inflammatory scores and airway hyperreactivity. So, the composition can be used to decrease airway allergic inflammation and modify the atopy sensitization.本發明係關於減低過敏致敏化及氣道發炎反應之醫藥組成物,其主要包含肝素,前述之肝素包括大分子肝素及小分子肝素。本發明之醫藥組成物尤其對於過敏性氣道發炎(特別是氣喘)具有中長期保護作用,經藥理實驗證明可有效減低血漿中過敏球蛋白,及減少肺部發炎因子、降低發炎反應,及氣道敏感性。故本發明之組成物可用於治療或預防慢性氣道發炎及改善過敏體質。