Thanks for your reply,

Actually i am done for mouse over  it's working fine for me,changing property name called "EnableHotTracking=False to True".Still i am having problem with itemtempleate group boder with while expending.

Problem :

1.Item templeate border width ,while expending the menu item.

Code example :  <igEx:WebExplorerBar ID="ProMISMenu" ImageDirectory="images" runat="server"
                                        BarWidth="100%"
                                        Width="145px"
                                        Height="100%" AnimationDuration="100" GroupExpandBehavior="AnyExpandable"
                                        AnimationEquationType="Bounce" EnableAjaxViewState="False"
                                        EnableTheming="True" GroupContentsHeight="" ItemIndent="7px"
                                        StyleSetName="Default" BorderStyle="None">
                                       
                                       <ClientEvents  ItemCollapsed="ProMISMenu_ItemCollapsed"
                                           ItemExpanded="ProMISMenu_ItemExpanded" ItemClick="ProMISMenu_ItemClick" />
                                       
</igEx:WebExplorerBar>

CSS Example:

.igeb_Control
{
 background-color:Transparent;
 font-size:large;
 /*font-weight:bold;*/
 font-family:Verdana, Segoe UI,  Helvetica, sans-serif;
 border:solid 1px #6593CF;
 border-top-width:2px;
 overflow: hidden;
 _overflow: hidden!important;
 color:Black;
 
 /*border-color:#6593CF;
 border-style:solid;
 border-width:0px;*/
}

.igeb_Group
{
 background-repeat:repeat-x;
 background-image:  url(images/igwlb_group_bt_normal.jpg);
 margin-top:5px;
 
 vertical-align:middle;
 text-align:left;
 background-color: #FEE17B;
  
 border-color:#6593CF;
 border-style:solid;
 border-width:1px;
 
 color:#003366;
 
}

.igeb_GroupSelected
{
 background-repeat:repeat-x;
 background-position:0px -60px ;
 color:#003366;
 background-image: url(images/igwlb_group_bt_normal.jpg);
}

.igeb_GroupActive
{
 background-repeat:repeat-x;
 background-position:0px -60px ;
 /*background-image: url(images/igeb_GroupBg.png);*/
 color:#0060BF;
 background-image: url(images/igwlb_group_bt_normal.jpg);
}

.igeb_GroupHover
{
 background-repeat:repeat-x;
 background-position:0px -30px ;
 background-image: url(images/igwlb_group_bt_normal.jpg);
 color:#0060BF;
}

.igeb_Item
{
 background-color:White;
}

.igeb_ItemImage
{
 padding-top:5px;
 padding-right:5px;
 padding-left:0px;
}
.igeb_ItemSelected
{
    text-align: left;
 color: #48AAF3;
 text-decoration: underline;
 padding-left: 5px;
 cursor:hand;
}

.igeb_ItemActive
{
 /*background-color:#FFCC33; /* selected Item in the field yellow */
 text-align:left;
 color:White;
 text-decoration:underline;
}

.igeb_ItemHover
{
 background-color: #48AAF3;/* selected Item in the field  yellow*/
 cursor:hand;
    text-align: left;
 text-decoration: underline;
 padding-left: 5px;
 
 /*background-image: none;
    color: Black;
    background-position: 0px 0px;*/
}

.igeb_ItemHover a:hover
{
    text-decoration: underline;
}

.igeb_ItemDisabled
{
}

.igeb_GroupContents
{
 margin-top:0px;
 margin-bottom:0px;
 margin-left:0px;
    padding-top:0px;
 padding-bottom:0px;
 padding-left:0px;
 list-style: none;
 
 /*border-color:#6593CF;
 border-style:solid;
 border-width:1px; */
}

.igeb_GroupLabel
{
 font-weight:bold;
 font-size:9.5px;
 font-family: Verdana, Arial, Helvetica, sans-serif;
 /*margin-left:0px;
 padding-left:0px;
 text-align:center;
 /*margin-top:2px;*/
 color: #204D89;
 border-width:0px;
}

.igeb_GroupDisabled
{
 background-repeat:repeat-x;
 background-position:0px -90px ;
 background-image: url(images/igeb_GroupBg.png);
 color:Gray;
}

.igeb_GroupExpanderImage
{
 /*margin-top:5px;*/
 margin-right:5px;
 float: right;
 /*up & down arrow change*/
}

.igeb_ItemLabel
{
 font-weight:normal;
 font-size:9.5px;
 font-family:Verdana, Segoe UI, Arial, Sans-Serif;
 display: block;
}

.igeb_Holder
{}

.igeb_GroupLink
{
 margin-bottom:0px;
 padding-bottom:0px;
 padding-left:6px;
 display: block;
 color: inherit;
 text-decoration:none;
 
 border-color:#6593CF;
 border-style:solid;
 border-width:1px;
}

.igeb_ItemLink
{
 padding-top:2px;
 padding-bottom:2px;
 display: block;
 color:#333333;
   text-decoration:none;
 /*color: #204D89;
 text-decoration: none;*/
}

.igeb_ItemParent
{
 background-repeat:no-repeat;
 background-image: url(images/igeb_Bullet.png);
}

/* IE 7 Disabled item fix */
.igeb_ItemDisabled a visited, .igeb_ItemDisabled a
{
 color:Gray;
}

.igeb_Group a visited
{
 color:#003366;
}

/* IE 7 fix to icon bad alignment*/
.igeb_Item ,.igeb_ItemActive ,.igeb_ItemSelected
{
 min-height: 30px;
 _height: 30px;
 /*border style */
 text-decoration:underline;
   /* background-color: #6593CF;*/
}

.igeb_GroupActive a
{
 color:#003366;
}

.igeb_GroupSelected a visited
{
 color:#003366;
}

.igeb_GroupSelected a
{
 color:#003366;
}

.igeb_GroupActive a visited
{
 color:#003366;
}

.igeb_GroupHover a
{
 color:#0060BF;
 
}

.igeb_ItemHolder img
{
 vertical-align:middle;
}

.igeb_Group a
{
 color:#003366;
 border-color:#6593CF;
 border-style:solid;
 border-width:1px;
}

.igeb_ItemHolder
{ }

.igeb_ItemContents
{
 margin-left:0px;
 padding-left:0px;
 list-style: none;
}

.igeb_GroupHover a visited
{
 color:#0060BF;
}

 please guide me to reslove above problem

Thanks

Ranganathan