Abstract: The characteristics and mechanisms of employment space in the fast-migrating city Shenzhen is studied, using the data of employment population, cell phone signaling and passenger data at subway stations. The following results are obtained. First, the center of the employed population in Shenzhen tends to move from east to west and then to north and a pattern of multi-center employment space is being formed. Second, the density of employed population shows a pattern of circles, decreasing from the central area to the middle area and to the peripheral area. Third, employment in the financial sector exhibits obvious concentric agglomeration, employment in the manufacture sector tends to be distributed peripherally, and employment in the consumer services demonstrates the dual characteristics of concentric agglomeration and peripheral addition. Fourth, the separation of work and residence is becoming more serious, leading to a large amount of commuter transportation across administrative districts. Fifth, industrial layout, transportation conditions, urban planning and housing prices are the main factors influencing the formation of employment space in Shenzhen. Finally, compared with the two non-immigrant cities Hefei and Shen-yang, Shenzhen undergoes faster development of employment space, new employment centers are formed more rapi-dly, a pattern of multi-center employment space has formed, and the separation of work and residence is more obvious with a greater average commuting distance between work and residence.