Abstract: In order to obtain more realistic simulation in warp knitting CAD system and provide more exact technologic design,it is necessary to develop a three-dimensional solid modeling of warp knitted structure and realize it on the computer screen.This article offered a 3-D solid model of the loop by using NURBS.By anti-calculating the control points of this model,the more exacted control polygon was gained and the real shape and position of space yarn can be described exactly. With program of Visual C++ and developing tools of Open GL,3-D simulation of warp knitted fabric can be realized visually on computer screen.As shown in the simulated graphics of basic warp knitted fabrics,this modelling can achieve good simulation effect.