This study was conducted to investigate whether exercise therapy applied in an efficacy expectation promoting program based on the self-efficacy theory of Bandura(1977) would increase self-efficacy and metabolism in NIDDM patients. The study design was a nonequivalent control group pre-test post-test quasi-experimental design. The exercise therapy applied in the efficacy expectation promoting program was composed of a staged exercise program, a small booklet relating personal experience with diabetes mellitus and a telephone coaching program on performance accomplishment, vicarious experience and verbal persuasion, which are all induction modes of efficacy expectation. The subjects of the study were twenty eight NIDDM patients who received follow-up care regularly through the out-patient department of endocrine medicine in one general hospital which had a diabetic clinic. Fourteen were assigned to the experimental group and fourteen to the control group. The experimental group participated in the exercise therapy applied in the efficacy expectation promoting program from three to five times per week for four weeks and the control group did not have the program. The collected data were analyzed using the x2-test, t-test, paired t-test, and Cronbach's Alpha using SPSS/PC+. The results are summarized as follows : 1. Experimental group had higher efficacy score than control group(t=5.98, p=.00). And, There was a significant different in the efficacy score before exercise therapy applied in the efficacy expectation promoting program and after in experimental group(t=-6.42, p=.00). 2. Experimental group did not have lower level of glucose metabolism than control group(FBS : t=.32, p=.75, HbA1C : t=.60, p=.55, pc 2hrs. glucose : t=-.29, p=.78). But, There was a significant different in the amount of glucose metabolism before exercise therapy applied in the efficacy expectation promoting program and after in experimental group(FBS : t=3.63, p=.003, HbA1C : t=4.20, p=.00 2hrs . glucose : t=1.93, p=.001). 3. Levels of lipid metabolism were partly a significant different between Experimental group and control group(triglyceride : t=-1.87, p=.07, HDL cholesterol : t=-.29, p=.77, body weight : t=1.78, p=.09, Total cholesterol : t=-2.17, p=.04). And, There was partly a significant different in the amount of lipid metabolism before exercise therapy applied in the efficacy expectation promoting program and after in experimental group(triglyceride : t=2.50, p=.03, HDL cholesterol : t=-.43, p=.67, body weight : t=5.34, p=.00, Total cholesterol : t=2.26, p=.04). In conclusion, it was found that exercise therapy applied in an efficacy expectation promoting program was an effective nursing intervention for increasing self-efficacy and metabolism.