The water resource shortages, water pollutions and urban waterlogging disasters have become increasingly prominent with the development of urbanization. Rainwater storage and utilization have become an important means of alleviating above-mentioned problems. This paper calculated the water balance between the collectable rainfall and the outdoor water consumption in Xianlin campus of Nanjing University and analyzed rainwater utilization measures to carry out conceptual design and comprehensive benefits evaluation of rainwater storage and utilization. The results showed that after rainwater storage and utilization, the comprehensive runoff coefficient of the study area decreased to 0.532 and the corresponding rainwater collected from the rooftops at the recurrence interval of 2, 5 and 10a can meet outdoor water demand. The corresponding monetary values of comprehensive benefits generated by rainwater utilization of per unit area will be 8 475.6, 10 506.3, and 11 786.4 yuan/hm2, respectively. Urban rainwater storage and utilization can produce significant ecological, economic and social benefits, and should be given sufficient attention in the development of new urban areas and the transformation of built-up urban areas.