use this bellow code..
- (void)viewDidLoad
{
UIImage *menuButtonImage = [UIImage imageNamed:@"list.png"];// set your image Name here
UIButton *btnToggle = [UIButton buttonWithType:UIButtonTypeCustom];
[btnToggle setImage:menuButtonImage forState:UIControlStateNormal];
btnToggle.frame = CGRectMake(0, 0, menuButtonImage.size.width, menuButtonImage.size.height);
UIBarButtonItem *menuBarButton = [[UIBarButtonItem alloc] initWithCustomView:btnToggle];
[btnToggle addTarget:self action:@selector(toggleCalendar) forControlEvents:UIControlEventTouchUpInside];
self.navigationItem.leftBarButtonItem = menuBarButton;
}