Provided a method for reducing an effective amount of Bevacizumab required for treating brain tumor. Also provided a kit used for the aforesaid method. The present method adopts a combination strategy to combine Bevacizumab treatment with ultrasound exposure, which comprises at least the following steps: administering Bevacizumab to a subject; administering an ultrasound-response medium to said subject; and administering said subject with an ultrasound exposure. Specific effective amount of the Bevacizumab treatment and the ultrasound exposure were identified. The efficacy of conventional Bevacizumab treatment is significantly improved.