This celadon vase has a flower shape mouth, a bulging belly with melon-shaped protrusions. Its glaze color is green (also known for Chinese “ fenqing” ) and its porcelain clay material is dark gray-white. This type of celadon is considered to be one of the official kilns of the Southern Song Dynasty, exclusively for the royal family at that time. It was used as a flower utensil. There is archaeological evidence that it may have come from the “Xiu Nei Si” Kiln.
 
Southern Song “Xiu Nei Si”  Kiln celadon is a precious porcelain of the Southern Song Dynasty (1127-1279), characterized by blue glaze. “Xiu Nei Si” was the institution that managed porcelain in the Southern Song court. The production process of Southern Song this Kiln celadon is very exquisite, with varied glaze colors, elegant shapes, and delicate patterns. It is a masterpiece of ancient Chinese ceramic art. The number of Southern Song Xiuneisi Kiln celadon is very small, and most of them are collected in museums or private collectors. They are very valuable cultural relics.
The last photo shows the sample from “Xiu Nei Si”  Kiln
 
Reference:
http://www.hues.com.cn/gudong/tc/show/?N_ID=8359
http://www.mastersart.org/index.php?m=content&c=index&a=show&catid=172&id=5292