Objectives : The main objectives of this study are to identify the factors associated with hypertension control and to determine the influencing factors associated with antihypertensive therapy. Methods : The study was conducted on 107 subjects who participated in the 1999 and 2002 Gwacheon Study and who had had uncontrolled hypertension (systolic$geq$140 or diastolic$geq$ 90mmHg) in 1999, We compared the characteristics of the controlled and uncontrolled hypertensive group and investigated the characteristics of those taking antihypertensive medication. Univariate associations between hypertension control and its characteristics and the association between antihypertension treatment and its characteristics were tested with $x^2$-test. We also peformed logistic regression analysis. Results : The participants who had their blood pressure checked within 6 months before their first measurement and those who had taken the antihypertensive medication showed significantly better hypertension control during the follow-up. The multivariate analysis showed that baseline antihypertensive therapy was the most important determinant factor of hypertension control during the follow-up. Socioeconomic level and life style did not affect hypertension control when controlled by the treatment variable in this study. The factors associated with antihypertensive therapy at follow-up were previous antihypertensive therapy, old age, and high educational level. Conclusions : Those who received antihypertensive therapy and those who had their blood pressure re-checked within 6 months both showed well controlled hypertension. The subjects with high educational level complied well with the antihypertensive regimen, but those in their forties did not.