The purpose of this study was to investigate the influence of group size on the response during a picture book-reading by the pre-school children. Five or six-year old children of kindergarten (N=28) were assigned to the "3 people" group and "8 people" group. The checklist was created from the responses observed during the picture book-reading. The checklist consisted of 16 responses categorized into 5 types, i.e., "utterance", "facial expression", "action", "gaze", and "response to other people" . Analysis of variance for each response, with group size ( "3 people" group, "8 people" group) and time section (first half, latter half) as independent variables, were performed. The main results were as follows: (1) The response to "see the child who talked" was higher in the "8 people" group than the "3-person" group, in the latter half. (2) The "laugh out loud" response was higher in the "8 people" group than the "3 people" group, in both the first half and the latter half. Based on these results, the features of each group size were discussed
