The three fundamental goals of early rehabilitation for preterm infant after leaving NICU are: optimizing function within each child's prognostic potential, preventing the development of secondary conditions that impact life-long health, and promoting children's participation and qualities in their lives. Understanding knowledges of these developmental patterns of Function and Participation in Life Activities (FPLA) and HRQOL may be helpful for anticipating and managing the problems. This study hypothesizes that the course of developmental patterns in FPLA and HRQOL of preterm infant evolve with their age. The functional recovery levels include developmental function, health, activity, participation, and quality of life (QOL). Since the previous plan only passed one year and encountered the COVID-19, the number of cases was not as expected. Therefore, this study will use the previous plan to test the functions of reliability, validity, and the evaluation of daily life participation to investigate the long-term performance of premature infants. Vertical development model under tracking. In addition, it is also expected to identify predictors related to the prognosis of preterm infants and compared with the healthy children of the Taiwan Early Childhood Development Survey Database (KIT) to find out the key differences in the developmental function and health of premature infants and healthy children. This study is a three-year longitudinal study of premature infants. It was carried out for three years. 60 full-term children aged 0-3 years and 150 premature infants aged 0-3 years were collected. A total of 210 children underwent a three-year period study. During the follow-up period, in addition to the initial evaluation, each subject will be followed up at 3 months, 6 months, 12 months, 18 months, and 24 months, toddlers( \>24months) will be followed up once a year according to the age of KIT's admission, and we will provide caregiver assessment report. We believe the results of this study will improve and support services provided to preterm infants.