『Abstract
　TerCharts is a comprehensive, fast, flexible, and versatile ternary charting utility that can be used for ternary data presentation analysis and modeling across many scientific disciplines. TerCharts is developed using Microsoft (MS) Excel 2003 and Visual Basic for Applications (VBA) which is an object oriented programming language developed by MS as a tool to enhance the capabilities of MS products. The Excel-VBA interface is important because normally chemical, geochemical, and mineralogical data used in teaching and basic research are processed using Excel spreadsheets, making TerCharts a more convenient tool for generating ternary charts which in turn can be used for data presentation and analysis. Ternary charts generated by this utility can be improved, edited, and modified utilizing MS Excel's powerful charting and editing techniques.

Keywords: Ternary chart; VBA; Excel』

Introduction
Description of the program
Using the program
　Input
　Output
Uses and examples
Concluding remarks
Acknowledgments
References