circRnA is a special type of non-coding RnA, which is closely related to the occurrence and development of many complex human diseases. However, it is time-consuming and expensive to determine the circRnA-disease associations through experimental methods. therefore, based on the existing databases, we propose a method named RWRKnn, which integrates the random walk with restart (RWR) and k-nearest neighbors (Knn) to predict the associations between circRnAs and diseases. Specifically, we apply RWR algorithm on weighting features with global network topology information, and employ Knn to classify based on features. finally, the prediction scores of each circRNA-disease pair are obtained. As demonstrated by leave-one-out, 5-fold cross-validation and 10fold cross-validation, RWRKNN achieves AUC values of 0.9297, 0.9333 and 0.9261, respectively. And case studies show that the circRnA-disease associations predicted by RWRKnn can be successfully demonstrated. in conclusion, RWRKnn is a useful method for predicting circRnA-disease associations. CircRNA, as a star molecule in the recent years, is a kind of non-coding endogenous RNA with single-stranded, closed and circular structure 1,2. Unlike the linear RNA, circRNA is the result of "back-splice" or derived from linear RNA. Hence, they lack 5′-3′ ends representing the RNA transcription's start and stop 3-6. The first circRNA was discovered by electron microscopy in RNA viruses 7 and afterwards in eukaryotic cells 8. Unfortunately, researchers regarded circRNA initially as a by-product of abnormal splicing without regulatory potential. Thus, circRNA did not attract much scientific attention 9. With the increasing researches on circRNAs, lots of circRNAs have been found in viruses, animals and plants 6,10-12. So far, circRNA has been confirmed to regulate multiple major biological processes, like cell invasion, proliferation as well as apoptosis 13,14. And circRNA is an important part in process of transcription 15 , mRNA splicing 16 , RNA translation and decay 17. Thus, the regulatory mechanism of circRNA is closely related to the occurrence of disease, which was identified by advanced biotechnology. For instance, the expression level of hsa_circ_0001982 in breast cancer tissues is significantly high 18. In addition, there are some circRNAs (Hsa_ circ_0014717 19 , CircMTO1 20 , Circ-PRKCI 21) that act as miRNA's sponge to regulate tumorigenesis. Therefore, it can provide new ideas for the treatment of diseases with acquisition and utilization of information related to circRNAs and diseases. In recent years, some circRNA-disease related databases have also been proposed to further investigate the associations between circRNAs and diseases, involving CircR2Disease 22 , circRNADisease 23 and Circ2Disease 24. The effective calculation methods based on these databases will effectively reduce the time consumption caused by the methods in biological experiments. Thus, it is urgent to use computational methods for exploring disease-related circRNA. Fan et al. 25 raised a simila...