This study was designed to determine the effect of self-efficacy, learning activities, and learning independence on biology learning achievement. This type of research is ex-post facto, namely causality which is designed to explain the existence of a causal relationship between variables. The population in this study was 603 high school students in Namlea Regency. The sample in this study amounted to 90 students. The data analysis technique used simple linear regression analysis. The results of the analysis show that self-efficacy has a positive and significant effect on the biology learning achievement of class X SMA Negeri in Namlea District. Judging from the results of simple linear regression calculations, it can be seen that the magnitude of the effect is 0.271, and the R value is 0.036. So it can be seen that the relative contribution of the effect of self-efficacy on learning achievement is 36.0%, while 64% is influenced by other variables not examined in the study.