Purpose: The purpose of this study was to develop a Community Intergenerational Observation Scale for Elders (CIOS-E) and Children (CIOS-C) to observe interactions between elders and children in intergenerational programs in the community and examine its reliability and validity. Method: Step 2 with 113 elders over 60 years of age and 130 children from six programs were recruited and their interactions were observed by the researcher using the initial forms CIOS-E (27 items) and CIOS-C (26 items) made from Step 1. Step 3 with an additional 174 elders and 175 children from 17 programs were recruited and their interactions were observed by the researcher using revised forms CIOS-E (18 items) and CIOS-C (16 items). Subjects completed a voluntary self-report questionnaire to evaluate their interactions and describe their satisfaction. Elders completed a Generative Concern Scale and SF-8 and the researcher used a Social Skill Scale to record observations of the children. Results: CIOS-E had three factors named Tolerance; Telling own history; Nurture. Measurement equivalence across Step 2 and Step 3 was accepted (p=0.078). CIOS-C had two factors named Succession and Respect. Measurement equivalence across Step 2 and Step 3 was accepted (p=0.392) CIOS-E and CIOS-C showed a Cronbach's α=0.79-0.81 and inter-observer reliability κ=0.73-0.88. Conclusion: CIOS-E and CIOS-C had reliability and validity to evaluate interactions between elders and children in intergenerational programs in the community.