Purpose: This study was conducted to determine factors affecting the positive feelings and care burden of elderly residents' primary caregivers in long-term care facilities. Methods: The survey was conducted between November and December 2018. A structured questionnaire was used to collect data, and 148 individuals voluntarily participated. The collected data were examined through descriptive statistical analysis using SPSS WIN ver.24.0, t-test, one-way Anova $Scheff{\acute{e}}$ test, Pearson's correlation coefficient, and multiple regression. Results: Factors that significantly affected caregivers' positive feelings included caregivers' education level(${\beta}=-.32$, p<.001), social support(${\beta}=.31$, p<.001), care burden(${\beta}=-.29$, p=.001), and total support fee(not more than 1.5million won)(${\beta}=-.18$, p=.012). The explanation power was as high as 40.0%(Adj $R^2=.40$). Factors that significantly affected caregivers' burden included social support(${\beta}=-.25$, p=.002), positive feelings(${\beta}=-.25$, p=.002), elderly individual's religion(${\beta}=-.17$, p=.007), and elderly individual's marriage status(${\beta}=.17$, p=.021). The explanation power was as high as 45.0%(Adj $R^2=.45$). Conclusion: Our results suggest that it is necessary to increase social support for elderly residents' primary caregivers in long-term care facilities. This can be helpful to decrease burden and enhance positive feelings in caregivers. We should also collect caregivers' information as well to provide appropriate assistance.