The fragmented and overlapped planning administration, evolved from the planned economy, is the institutional foundation of the spatial planning system in China. Together with the problems of development control, spatial plan coordination of FYP, land use planning and urban planning in urban China thus has been concerned for a long time. This paper explores the dilemmas and relevant mechanisms of spatial plan coordination by a case study of Suzhou city. The empirical analysis shows that local spatial plans were highly constrained by the sectoral codes, hierarchic regulations and the controlling system of various quotas beyond the city level. The primary contradictions among the three plans were rooted in the planning parameters of the land area for construction and the spatial regulation on land use. The sectorally improved planning administration increased the complexity of plan coordination on the one hand. On the other hand, embedded in the different philosophies of the central and local governments over land governance, various spatial plans have become their complicated arenas and the planning process was mixed by central control and local initiatives. Subsequently, under the nested institutions of planning making, local spatial planning was manipulated and intervened, and thus spatial plan coordination failed.