Blue and white is a kind of underglaze cobalt blue. It is an underglaze painted porcelain which is colored with cobalt material on a porcelain tire, coated with transparent glaze and fired at a high temperature at one time. Because cobalt is blue after high temperature firing, it is called "blue and white".

Mature blue and white porcelain appeared in the Yuan Dynasty, but its origin can be traced back to the Tang Dynasty. The existence of Tang Qinghua has been confirmed by current archaeological excavations. Tang Qinghua was found in tombs, city ruins and sunken ships at the bottom of the sea. In addition, some folk collectors also collected Tang Qinghua's specimens or complete vessels. More importantly, a kiln site for burning Tang blue and white flowers was found in Gongxian kiln site, Henan Province. The academic research on Tang Qinghua has achieved fruitful results. Although they have different understandings and viewpoints, they have reached a consensus in many aspects.

But blue and white became the mainstream of Ming porcelain. It reached its peak in the Kangxi period of the Qing Dynasty. During the Ming and Qing Dynasties, colorful blue and white, peacock green glazed blue and white, bean green glazed blue and white yellow and old glazed blue and white were also created and fired.

However, blue and white flowers were also found in archaeological excavations in the Song Dynasty, but there are many controversies at present. Because there are too few physical materials, many books and papers have a brief description of Song Qinghua, and some scholars hold negative opinions on his existence. For example, some scholars believe that the age of blue-and-white porcelain pieces of the Song Dynasty unearthed from Jinsha Pagoda in Zhejiang and Huancui Pagoda in Shaoxing has been advanced. "We can't simply say that there was blue and white in the Tang Dynasty, there must be blue and white in the Song Dynasty, and there must be blue and white in the Yuan Dynasty." "Due to the great contingency of historical development and various factors, as a skill, it is entirely possible to be interrupted and re-invented after being silent for centuries." In addition, the vast majority of folk collectors also hold a negative attitude towards the existence of Song Qinghua. When it comes to Song Qinghua, most people call it "fabrication" in a conditioned way.