Try:
Obj.id=1;
Obj.name="AA";
TimerObj.Interval = 1000;
TimerObj.Tag = Obj;
Obj.TimerObj.Tick += new EventHandler(Timer_Tick);
...
private void Timer_Tick(object sender, EventArgs e)
{
Timer t = sender as Timer;
if (t != null)
{
class1 c = t.Tag as class1;
if (c != null)
{
...
}
}
}