Nassi-Schneiderman (N-S) charts are similar to flowcharts, but are more concise and have built-in support for common operations like decisions and loops. It has simple structure elements, but its ability of describing algorithm need further study. In this paper the normalization analysis of N-S flowchart is discussed with its rules of hiberarchy, neighbour, connotation, and its extensibilities, including inclusive term, semantic planning, and specification, are presented. Experimental examples indicate that it has some advantages with N-S flowchart applications in algorithm description.