Objective:To establish a C57bl/6 mouse asthma model the ovalbumin(OVA)free and to evaluate the model using dexamethasone(Dex). Methods:Clean female C57bl/6 mice fed without OVA for over 3 generations were divided into three groups(n=36,12 for each group). The asthmatic group was sensitized by i.p with OVA aluminium hydroxide gel on day 1 and 14. From 21 st day,asthmatic group was aerosolized 1.5% OVA for 7 days. The control group received saline as the substitution of OVA. The treated group was i.p with 5 m...