Abstract: Objective: To explore the effects of different combined regimen of β-Carotene plus vitamin E on the immune function of mouse treated by chemo-radiotherapy and find the best combined regimen and suitable dose level. Methods: Orthogonal design (L₈(2⁷)) was used to observe the effects of the combination of different β-Carotene plus vitamin E on immune function after chemotherapy or radiotherapy. Twenty-four mice were divided into 8 groups and oral administrated by different dose combination of β-Carotene and vitamin E on 21^th day, then they were treated by chemotherapy (60mg/kg/ d x5 times) or radiotherapy (4Gy). Tests were performed from 7th day after treatment. Results:β-Carotene played a bigger role than vitamin E on the immune function effects, and the combination of high doseβ-Carotene and low dose vitamin E showed better effects than others. Conclusions: The combined regimen with 60mg/kg+17mg/kg of β-Carotene plus vitamin E is better than other regimens in enhancing the immune function.