The purpose of this study was to investigate epistemological predictors of nature of science understandings of 281 prospective biology teachers surveyed using the Epistemological Beliefs Scale Regarding Science and the Nature of Science Scale. The findings on multiple linear regression showed that understandings about definition of science and objectivity in science were negatively predicted by beliefs in inborn learning ability (ILA) and requirement for time in learning (RTL), while understandings about tentativeness was positively predicted by the same belief factors. Also, understandings of characteristics of scientific knowledge were positively predicted by beliefs in ILA and RTL, and hierarchy between laws and theories were negatively predicted by beliefs in ILA, RTL and development of learning ability with opportunity and support.