private void axMapControl1_OnMouseDown(object sender, ESRI.ArcGIS.Controls.IMapControlEvents2_OnMouseDownEvent e)

        {

            //产生一个简单符号

            ISimpleMarkerSymbol pMarkerSymbol = new SimpleMarkerSymbolClass();

            pMarkerSymbol.Style = esriSimpleMarkerStyle.esriSMSCross;

            pMarkerSymbol.Color = GetRGBColor(, , );

            pMarkerSymbol.Angle = ;

            pMarkerSymbol.XOffset = ;//符号偏移鼠标点击点横坐标的距离

            pMarkerSymbol.YOffset = ;//符号偏移鼠标点击点纵坐标的距离

            //产生一个箭头符号

            IArrowMarkerSymbol pArrowMarker = new ArrowMarkerSymbolClass();

            pArrowMarker.Length = ;//箭头的顶点到底边的距离

            pArrowMarker.Width = ;//箭头的底边的宽度

            pArrowMarker.Color = GetRGBColor(, , );

            pArrowMarker.XOffset = -;

            pArrowMarker.YOffset = -;

            //产生一个叠加符号并把前面的符号加入

            IMultiLayerMarkerSymbol pMulMarker = new MultiLayerMarkerSymbolClass();

            pMulMarker.AddLayer(pArrowMarker);

            pMulMarker.AddLayer(pMarkerSymbol);

            IPoint pPoint = new PointClass();

            pPoint.PutCoords(e.mapX, e.mapY);

            object o = (object)pMulMarker;

            axMapControl1.DrawShape(pPoint, ref o);

        }

        private IRgbColor GetRGBColor(int red, int green, int blue)

        {

            IRgbColor pRgbColor = new RgbColorClass();

            pRgbColor.Red = red;

            pRgbColor.Green = green;

            pRgbColor.Blue = blue;

            return pRgbColor;

        }from:http://blog.sina.com.cn/s/blog_71d88f280100mj5z.html