Try this....
<asp:listitem text="India" value="0" xmlns:asp="#unknown">
<asp:listitem text="Usa" value="1">
<asp:listitem text="china" value="2">
<asp:listitem text="japan" value="3">
or
in code behind
ddl_country.items.insert(0,"India");
ddl_country.items.insert(1,"japan");
.......
</asp:listitem></asp:listitem></asp:listitem></asp:listitem>