人口密度是研究人口分布格局所使用的一个指标。然而以往的研究对人口密度的尺度效应没有给予应有的关注。本文以沈阳市为例，在对人口统计数据进行空间化处理的基础上，从统计特征、空间自相关性和空间格局三个方面分析人口密度在十种粒度下的异同，充分证明了人口密度尺度效应的存在，并基于景观指数确定了沈阳市人口分布研究的适宜尺度。本研究认为在使用人口密度这一指标来研究城市人口分布格局时，学者们必须面对尺度效应、选择适宜尺度，并充分考虑数据来源的尺度、分析的尺度、结果表达的尺度以及他们之间的关系和转换。

Population density is an index of studying population distribution pattern. But scale effects of population density have not been paid attention that should be paid in the past. Studying Shenyang city as a case, after spatializing population census data, this paper analyzes similarities and differences of population in ten kind of grains from statistical characters, spatial auto-correlation and spatial pattern, and proves that there are scale effects in population density. This paper argues that when using the index of population density to research urban population distribution pattern, the researchers have to confront scale effects, choose feasible scale, and pay more attention to scale of data sources, scale of analyzing, scale of results expressing and relationship among them and scaling.