Objectives: To develop items for an early screening index for teachers to screen infants and young children (aged 1-5 years) at risk of disability in kindergartens and daycare centers, this study examined the reliability, validity, and difficulty of items for the standardization study. Methods: Based on literature review and expert advisory meetings, the first version of items related to daycare centers and kindergarten routines was developed. Items were divided into 9 routines for 7 age groups. The second version of items was selected by expert review, and FGI with 28 teachers was conducted to verify the validity of the first version. Data on 395 children collected from 232 teachers were analyzed using SPSS 12.0 to assess the reliability, validity, and difficulty of items. Results: The internal consistency for the second version comprising 349 items was .997, and that for each developmental area was very high ranging between .97 and .98. The final version of the Korean Screening Index for Early Development (K-SIED) for the standardization comprised 376 items with extra items developed by experts. The number of items ranged between 43~57 items for each age group. Conclusion: To develop an early screening index teacher form, 376 items were created for 7 age groups of 1-5-year-olds. The index can be used as a tool for early screening to guide the family for diagnosis and necessary interventions after the nationwide standardization in 2024. Together with the early screening index parent form, the K-SIED teacher form will facilitate early intervention.