Purpose – The purpose of this paper is to introduce a participatory library service based on artificial intelligence (AI). Design/methodology/approach – AI technologies and various technologies for facilitating the use of the currently existing libraries and the third-party resources are combined in the new mobile and social networking environments to provide an innovative real-time virtual reference service. Special aesthetic design and library marketing measures are adopted to expand the gains of the service. Questionnaire survey, in-depth interview, and statistical analysis are conducted to evaluate the effects of the service. Findings – A smart talking robot called Xiaotu (female) is developed. This robot is regarded as a promising new online reference service modus operandi. Four factors contribute to the success of the robot, namely, AI, self-learning, vivid logo and language, and modular architecture. Practical implications – Xiaotu presents a participatory library service, in which users participate in the resources collection and become content co-creators. Her presence at anytime and anywhere on any kind of terminal maximizes her potential for the delivery of virtual reference services. Xiaotu has the potential to be a general reference robot or a costumed institute robot. Originality/value – AI is adopted in libraries to form an innovative online reference service. The participatory library service is practiced through a high-featured interactive communication. The aesthetic design of Xiaotu and the related promotions are new in libraries as well.