This study aimed to determine simultaneously and partially the effect of mathematical resilience and students' perceptions of online lectures on the mathematical power of students of the mathematics education study program, Unika Santu Paulus Ruteng. This research used an ex post facto approach. The population in this study were all first-years students of the mathematics education study program Unika Santu Paulus Ruteng. The sampling technique in this study was simple random sampling, so the sample was 30 students. The data were collected by questionnaires and tests. The questionnaire was used to collect data on mathematical resilience and student perceptions about online lectures, while the test was used to collect data on students' mathematical power. Data were analyzed by multiple linear regression. The linear equation obtained was Y = 20.233 + 0.498 X1 + 0.227X2, so the results showed that there was a simultaneous and partial effect on mathematical resilience and perceptions of online lectures on students' mathematical power.