In the era of big data,urban big data is the key to change the way of urban development,improve people’s living standard and offer new impetus to economic growth,so top-level design,system planning and promoting measures must be done.Firstly,the concept,connotation,boundary and classification of urban big data,and opportunities and challenges may appear in the process of developing China’s urban big data were analyzed.Then,a service architecture of urban big data which including an integrated foundation support framework,an application framework,an industrial framework,an index framework and maintenance framework was proposed.Finally,the implementation path and some suggestions to constitute the service center of urban big data were given.