fMRI is widely used to investigate the spontaneous activity of the brain. In this paper, a quantitative analysis method is proposed to describe the relationship between the BOLD features of resting-state fMRI and the tumorous growth of brain tissues. In our method, a map of tumorous possibility degree is detected from tissues structural images of MRI and coregistered into the functional space. After extracting the BOLD features, further analysis is done to reveal the relationship between functional signal and tumor growth. The average value of BOLD signal is found as a significant feature of tumorous tissues and resultantly presents a positive correlation with the degree of tumorous possibility. The same method is also applied in the analysis of the most commonly used BOLD features include ALFF and ReHo. In the results the two features show a negative correlation with the tumorous possibility degree. The method proposed in our study is based on multimodal signal combination of tissues structure and functional features. It should be a valuable method and serve as a basic understanding for explaining how the tumor influences brain function and further for rebuilding the functional network.