The purpose of this study was to examine the effect of diabetes education on diabetic management by determining the changes of the knowledge and practice for diet therapy and blood glucose level pre-training and post-training. Statistical data analyses were completed using the SPSS 11.0 program. The results can be summarized as follows : The average age of the subjects was 52.8 years old, the period of suffering from diabetes was 7.9 years and 31% of the patients had a history of diabetes in their family members. In life style for self-management, they showed lower levels in drinking post-training, and significantly higher exercise levels post-training (P<0.05). Regarding the level of knowledge for diet, they showed significantly higher levels post-training in eight items such as importance of diet therapy for diabetes (p<0.005), principle of diet therapy (p<0.005), nutrient composition of foods (p<0.005), carbohydrate composition of foods (p<0.005), calorie prescribed to themselves (p<0.001), exchange units prescribed to themselves (p<0.005), exchange food items and exchanges units of cereal & grains (p<0.005) and exchange food items and exchanges units of fruit & juices (p<0.005). Regarding the practices of diet, they showed significantly higher levels of practice in keeping permitted meal size (p<0.005), using food exchange list (p<0.005), keeping exact meal times (p<0.001) and restricting most foods to eat (P<0.01) post-training. When measuring their bodies, average weight was lower post-training. Obesity was significantly lower post-training (p<0.01), and blood pressure both in systolic and diastolic was lower. Postcardinal-2hour blood glucose level decreased significantly from 268.4$pm$98.9 pre-training to 180.9$pm$48.4 post-training (p<0.001).