This website has much information about the paintings in Siena.I learned many special skills of painting.This website helps me a lot.

This painting is painted by Duccio di Buoninsegna.
I chose it because I like the its background .
The artist may kneaded the paper before painting it to make it looked more textural.This way of painting is very special.
In addition,although Buoninsegna didn't use so many colors on the work,you can always notice it because of its contrast.
That is why I chose it.
http://www.flickr.com/photos/mcd/310512858/

This painting is also from Buoninsegna.
There were many paintings of The Last Supper in this time,but this one is one of the most special ones.It makes people fell another atmosphere from this paintiong.
It looks very plain,but you can "enter" it.The artist used more linesto show the perspective,but it still looked a little flat.
I think that perhaps it is the most different style from between then and now.
(Until now,I still don't know why there are circles over some man's head.
I guess that the artist may want to show the status of them...it comfuse me a lot.