Evaluation of plan implementation is very complex, and empirical study is scarce due to the methodological difficulties. Over the last two decades, there has been a great deal of urban planning activities and rapid city development in China, but there is a lack of evaluation of plan implementation. This research aims to help bridge this gap, and it explores to what extent a plan has been implemented and what factors have affected plan implementation, taking the Guangzhou city master plan as a case study. It adopts the grid overlay method and compares the land use plan and actual land use to obtain the result of accordance, deviation and unfulfilment. The discrepancy between the land use plan and actual land development is examined based on both land use type and the spatial planning management unit. By analyzing several cases at the site development control plan level, this paper explores why the land development is not consistent with the land use plan.