The purpose of this study was to examine factors influencing on depression among elderlies of activity of daily living, participation of social activity, loneliness, stress in COVID-19 pandemic. Methods: The research design for this study was a descriptive survey using convenience sampling. Data collection was done using self-report questionnaire of 142 elderlies in D city and K province. Collected data were analyzed using percentage, mean, standard deviation, independent t-test, one-way ANOVA, Pearson’s correlation analysis, step-wise multiple regression. Results: Total mean scores of activity of daily living was 3.66±0.52, total mean scores of participation of social activity was 2.77±0.58, total mean scores of loneliness was 2.09±0.43 and total mean scores of participation of depression was 9.97±4.45. Depression was showed significantly positive correlation with loneliness (r=0.67, p<0.001), stress (r=0.10, p=0.260). Depression was showed significantly negative correlation with activity of daily living (r=-0.49, p<0.001), participation of social activity (r=-0.54, p<0.001). In the step-wise multiple regression analysis, loneliness, activity of daily living were significant predictors and explained 54% of depression. Loneliness was the biggest predictor of depression. Conclusions: The results of this study showed that loneliness and activity of daily living are significant factors affecting the depression of elderlies in the South Korea community in COVID-19 pandemic.