With pixel un-mixing, the omission of pixel caused by mixed pixel can be resolved so as to improve the classification accuracy. But the trouble is only the proportion of each end member object in one pixel which can be got through pixel un-mixing, while the spatial distribution of is uncertain. The objective of this study is to introduce the sub-pixel mapping based on spatial attraction model and explore some issues of it, such as neighboring pixels selection and spatial attraction normalization. As the experiments proven, the sub-pixel mapping could get better result by the eight neighboring pixels selecting mode and normalizing by sub-pixel mode in most cases.