Objectives: The aim of this study is to use Rasch-based approach methods to assess the change of quality of life (QoL) scores and the effects of its predictors among patients with type 2 diabetes across three years’ follow-up period in Taiwan. Methods: We followed 205 patients recruited in July 2006 from one medical center in northern Taiwan during outpatient visits in the metabolism special clinic and general clinic of the study hospital in May 2009 to Jan 2010. The Diabetes Quality of Life (DQOL) questionnaire was used to assess the disease-specific QoL. Socio-demographic characteristics, diabetes-related factors and other medical factors were also collected as possible predictors. The psychometric properties of DQOL three domains (DQOL-S (satisfaction), I (impact) and W (worry)), and change of DQOL scores were examined by Rasch methods separately. Multiple linear regression models were used to test the association between possible predictors and the change of DQOL scores in the three years. Results: Of the 202 patients followed (after exclude 3 patient with type 1 diabetes), 149 patients completed the follow-up interview (mean age of 61±11 years). In psychometric properties, all items fitted Rasch method’s expectation except the item of “sleep” and “control of diabetes” in DQOL-S and “reluctant ” in DQOL-I. After removal of the misfit item, all of the remaining items all fitted the requirement of unidimensionality. In distribution of patients’ response and item difficulty, patients covered almost the full range on the construct of DQOL-S, while potential ceiling effects in structure of DQOL-I and DQOL-W. During the 3-year study period, patients showed a statistically significant increase on satisfaction level in satisfaction (p<.0001) but also a higher level of worry (p=0.01). After adjusting for all of potential predictors, presence of microvascular complications (neuropathy and nephropathy) and ever using insulin therapy were associated with a deterioration of worry scores. Starting exercise and / or diet control had positive effect on change in satisfaction and worry scores (p=0.01). Conclusion: Three domains in DQOL represent one common construct. In this cohort of patients with type 2 diabetes, the presence of complications is predictive of a lower QoL, while starting exercise and diet control predicting positive change of QoL. Effect of change of HbA1c values was not seen in this study.