100% cotton. It's thin, so you can wear it from early summer through fall by pairing it with a cardigan. The fabric itself has a woven pattern, and although it's cotton, it doesn't cling to the skin. It also doesn't wrinkle after washing. I loved it and wore it for two seasons. It's still wearable, but I've outgrown it (ToT), so I'm selling it at a low price.