Ok - Just do this.
If you have rootViewController, in viewDidLoad method - just place following line.
( Default view controller in "Navigation based application")
Whatever view controller you have to place following code.
- (void)viewDidLoad
{
[super viewDidLoad];
// if it your view controller extends - UITableViewController
[self.tableView setSeparatorColor:[UIColor clearColor]];
// or
// your placed tableVCtr on .xib & have datasource & delegate & table connections
[mytableVCtr setSeparatorColor:[UIColor clearColor]];
}