Chang-ao is the traditional Chinese attire for women. It is a form of formal wear, and is often perceived as a longer version of ruqun

Ruqun

Ruqun is an item of traditional Chinese attire primarily for women. It consists of a blouse and a wrap-around skirt . It has a long history, and has been worn by women since the Warring States Period.-History:...

. However, it was actually developed from zhiduo during the Ming Dynasty

Ming Dynasty

The Ming Dynasty, also Empire of the Great Ming, was the ruling dynasty of China from 1368 to 1644, following the collapse of the Mongol-led Yuan Dynasty. The Ming, "one of the greatest eras of orderly government and social stability in human history", was the last dynasty in China ruled by ethnic...

, and is worn over a skirt. It is wide-sleeved, shorter than zhiduo and has no side panels (暗擺) at the side slits (thus showing the skirt worn underneath). There is often an optional detachable protective huling (護領, lit. "protect collar") sewn to the collar. The huling can be of white or any other dark colours. The collar is of the same colour as the clothing.