Dear Editor, Please see my poster details attached for uploading to your website. Thank you very much for your help! Cheers, Huiyun Subject: Enhancing Intergroup Relationship Between Local and Mainland College Students in Hong Kong – Randomized Controlled Trial of an Intensive One-Day Intervention Grounded in Intergroup Contact Theory Abstract: This study examined the efficacy of an intensive one-day intergroup contact workshop for two rival groups: local and mainland Chinese college students in Hong Kong. The differential impacts of contact intimacy at cognitive, interpersonal, and emotional levels in fostering changes in knowledge, attitude and behaviour were evaluated. Adopting a two-arm Randomized Controlled Trial (RCT) design, participants (N = 72) were randomly assigned to intervention group, which facilitated progressively higher levels of contact intimacy, or control group with limited level of contact intimacy. The results support the short-term efficacy of the intervention in enhancing outgroup knowledge, attitude, and behaviour, with Cohen’s d of 0.97, 0.60 and 0.30, respectively. Specifically, cognitive-level intergroup contact enhanced outgroup knowledge only. Adding on interpersonal-level intergroup contact further enhanced outgroup attitude. Lastly, adding on emotional-level intergroup contact enhanced changes in all three domains: knowledge, attitude and behaviour. One-month maintenance effect was preserved in outgroup knowledge only, with Cohen’s d increasing to 1.33.