本文介绍了定量化研究多个种子植物区系的电子计算机程序（DDAI）工作原理,简要讨论以共有属构建的区系间相似关系问题。应用本文提出的程序,可一次性完成所有被研究区系种子植物分布区类型的统计及有关的计算工作,同时也可根据各分布区类型及总体共有属,构建各个区系间的相似性系数及其他有关的参数。本文以中国若干种子植物区系原始资料统计计算为例提供的CAR（Computer Aided Research）方法,可对全面深入地研究中国种子植物区系,提供强有力的工具。 

In this paper, the Computer Aided Research (CAR) method is adapted to the field of floristic studies, and a series of computer programs (DDBJ- series) are worked out and introduced here. The process of the computer programs for the quantitative study on different floras is explained in detail. The similarity coefficient obtained from the calculation of common genera among regional floras is mainly discussed. These programs can be used for the statistical analysis of the genera distribution types of any given floras in one time, and they can also make out various kinds of similarity coefficients according to the number of common genera among different floras. Some original flora data gained from different parts of China are treated with DDBJ to illustrate the working process of these programs. It is hoped that DDBJ-series programs could be used as a very useful tool in the comparative floristic study of Chinese seed plants.