The paper carries out case analysis from the four aspects of the initiating background, targets and characteristics, service effect and improvement measures of the "AIDS Community Information Outreach Program (ACIOP)" of the National Library of Medicine(NLM). It summarizes the enlightenment to the public health information service developed by China's medical library, including abundant information resource base, targeted thematic information service, cooperation with front-line institutions and attention paid to service management and effect assessment.