Trading Activities with China
Existence of Shilla society in Tang even before the positioning of
   Cheong-Hae-Jin


Organized a unified society for Shilla people in Tang and Used it as a base    for trade and goods


Provided guidance service for Japanese envoys, monks, travelers, or    merchants by Shilla

 
- This proves that the trading activities of Shilla society was at a large scale at
  that time.


Gyeon-Dang-Mae-Mool-Sa (Commercial Envoys to Tang of China)

Chang Po-go dispatched a group of Commercial Envoys to Tang boarded on a his
  own fleets called Gyo-Gwan-Seon.
"The trade ship, Gyo-Gwan-Seon, that Choi Byeong-Ma-Sa boarded traveled to
  Yang Zhou back and forth for trade."(Record of Pilgrimage for the Truth of
  Buddhism by Ennin on February 15, 840)
Shilla merchant ships traded not only with China, but also with Su Zhou, Yang
  Zhou, Ning Bo, Arab, and Persia at that time.


Import of Manufacturing Skills of Koryo Celadon

Until now, it is estimated Koryo Celadan began to be made from the 10th
  century from archeological viewpoint (Ming Dynasty's Celadon Pottery, 993)
  there is an opinion that the manufacture of celadon in Korea started by
  importing porcelain making skills from Yue Zhou, Zhe Jiang Sheng in the latter
half of the 9th century.