Abstract: Since the reform and opening up, with the deepening reform of urban land and housing market, the process of rapid suburbanization and urban sprawl as well as the disintegration of danwei institution, dramatic changes have taken place in jobshousing spatial organization in big cities of eastern China, such as Beijing, Shanghai, Guangzhou et al, which have already led to transportation problem and changes in urban commuting pattern. Because all studies on the characteristics of jobshousing space focus on the big cities of eastern China, there is no detailed investigation for the big cities of western China which belongs to undeveloped areas. This paper chooses Lanzhou City which situated in western China as a case to study its characteristics of jobshousing space. So, it is interesting to compare the jobshousing space in Lanzhou City with that in big cities of eastern China. It is also interesting to find out if the problem of the separation between jobs and residential locations in Lanzhou City is as serious as that in big cities of eastern China. This research has important meanings in guiding the city department of urban planning to pay more attention to the jobshousing balance in the future. Such study also builds a bridge between commuting research and urban internal structure study, and offers a dynamic angle for further research. The study is based on the questionnaire answered by nearly 2 500 people in 2010, and then use GIS technology to calculate straightline distance between job and housing places as commuting distance. Based on the case study, we find that the average commuting distance is 2.34 km, and half of the commuters travel less than 1 km. This suggests that the average commuting distance in Lanzhou City is much shorter than that in big cities of eastern China; therefore the problem of separation between jobs and residential locations is not serious. Lanzhou City, as a multicenter linear group city, has achieved the balance between jobs and residential locations in every group. Most of residents commute in the group where they live, so the commuting distance is not very long. The characteristics of jobshousing spatial organization vary from group to group. The average commuting distance is shorter in Chengguan and Anning districts, but it is longer in Qilihe and Xigu districts. The difference of jobshousing spatial locations accounts for the characteristics of commuting flows in the city. The main commuters flows are inward in Chengguan district. The flows of the commuters achieve a bidirectional balance in Qilihe district. Outward flows are the main commuter flows in Anning and Xigu districts, although there are inward flows at the same time.

Key words: jobshousing spatial organization, commuting distance, jobshousing balance, Lanzhou City