中医方剂学是研究中医方剂的组成、功效和临床应用等问题的一门科学。临床使用方剂,一般都要对原方的药味和药量进行加减化裁。但这种加减化裁,应有一个界限或范围,如果某种加减变化,突破了这个界限或范围,就不宜再称原方剂名称的加减了。我们把这种界限或范围,叫做中医方剂的“组成规范”。历来方剂学 TCM prescription science is a science that studies the composition, efficacy and clinical application of TCM prescriptions. The clinical use of prescriptions generally requires addition and subtraction of the original taste and dose. However, such additions and reductions should have a boundary or range. If a certain change is added or subtracted to break through this limit or range, it is not appropriate to add or subtract the name of the original prescription. We call this boundary or scope the “composition specification” of Chinese medicine prescriptions. Historical formulae