Objectives: The aim of this study was to construct and verify a structural equation model of advance directive intent among a Korean group in their middle-age. Methods: Data were collected between May 1 and 30, 2017, from 398 people. The endogenous and exogenous variables of the hypothetical model consisted of elderly parents' care burden, health status, attitude towards withdrawal of life sustaining treatment, advance directive efficacy, and advance directive intent. The collected data were analyzed using the SPSS/WIN 24.0 and Mplus 7.4. Results: The hypothetical model demonstrated a good fit: χ2=223.79(df=109, p<.001), CMIN/df=2.05 CFI=.96, TLI=.96, RMSEA=.05, SRMR=.06. Elderly parents' care burden and health status showed statistically significant direct effects with attitude toward withdrawal of life sustaining treatment(β=.17, p=.001; β=.21, p<.001) and advance directive efficacy(β=.11, p=.040; β=.19, p=.002), respectively. Attitude toward withdrawal of life sustaining treatment and advance directive efficacy showed statistically significant direct effects on advance directive intent(β=.15, p=.007; β=.48, p<.001). Elderly parents' care burden and health status had a significant indirect effect on advance directive intent through attitude toward withdrawal of life sustaining treatment(β=.01, p=.041; β=.05, p=.036) and advance directive efficacy(β=.06, p=.049; β=.16, p=.006), respectively. The variables accounted for 26.1% of advance directive intent of the Korean group in their middle-age. Conclusion: It is necessary to develop an advance directive education program based on variables affecting advance directive intent for individuals in their middle-age.