Well, the correct usage is "In The Morning". But you can say - At morning time, At morning church, At morning break, At morning prayers, At morning walk, At morning tea break etc.

Thanks a lot to all of you for your quick answers...:)

I think "In the morning" is correct. I cannot think of a situation where I would say at morning.

Use "in the morning". The only time you'd use "at" is in the "red sky at morning" saying.