Hi,

Here I have created sample that will help you out.

HTML

<div>
    <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
    <script type="text/javascript">
        function SetCheckBox() {
            var lableValues = $('[id*=lblValues]').html().trim().split(',');
            $("[id*=chkFruits] input").removeAttr("checked");
            $(lableValues).each(function () {
                $("[id*=chkFruits] input[value='" + $(this)[0] + "']").attr("checked", "checked");

            });
        }       
    </script>
    <asp:Label ID="lblValues" Text="a,b,c" runat="server" />
    <asp:CheckBoxList ID="chkFruits" runat="server">
        <asp:ListItem Text="a" />
        <asp:ListItem Text="b" />
        <asp:ListItem Text="c" />
        <asp:ListItem Text="d" />
    </asp:CheckBoxList>
    <asp:Button Text="setCheckboxList" runat="server" OnClientClick="SetCheckBox()" />
</div>

Screenshot

For more information please refer below article

Check Uncheck all items in ASP.Net CheckBoxList using jQuery