Abstract: This paper presents a very handy descriptive language used for mechanic graphing and a corresponding powerful graphic system,so as to meet the present requirement of domestic computer aided mechanical graphing field.This system possesses important graphic features of easy input,shifting,rotating and reflexing,and a strong handling capability for sectional field.This system has a character library(including Chinese characters and special characters)dedicated specially to drawing notation.This system is written in FORTRAN language in order to be easily transfered tolarge and middle sized computers as well as micro-computers with bigger storage.