The most usual problems encountered in the structure handling are tautomerism, alternating and aromatic systems. Though a number of methods have been reported in the literature, a common disadvantage is that only the convenience for processing were taken into account, but their chemical sense was rarely considered. Thus their application is limited. Based on the identification of ring system, novel algorithms have been devised in order to enhance the overall performance and a software with copyright has been developed. This paper introduces these algorithms and their potential applications by examples.

Key words: CHEMICAL BONDS, COMPUTER APPLICATIONS