Chinese scholars describe Balhae culture as follows: Mohe culture (Tungusic people in ancient Manchuria) is the foundation for Balhae culture. After the founding of Balhae, its culture developed under a strong influence of Tang dynasty culture. This is supported by Balhae's efforts to export culture through the numerous envoys sent to the Tang dynasty. As Balhae was a subordinate state of the Tang dynasty, the only cultural distinction between the two is on a central and local level.
It is true that the Balhae culture contains elements derived from the Mohe and Tang dynasty. However, the influence of Koguryo culture is more significant. Influence of Koguryo culture can be clearly seen in the remains of walls, roof tiles, under-floor heating, and Buddhist structures dispersed throughout Kraskino in Primorsky Krai, Russia or the former Balhae capital Sanggyeong. This fact was reaffirmed through an official hat that was discovered in the Dragon Sea burial zone of Helong in Jilin Province, China. The hat bore a striking resemblance to Koguryo's unique official headwear, the Jougwan.
In addition to the trade route with the Tang dynasty, Balhae also shared trade routes with Silla, Japan, and Khitan. Balhae actively traded with several other East Asian states as well as the Tang dynasty. In this sense, it's reasonable to believe that Balhae exchanged culture and influence with various East Asian states including the Tang dynasty.
Examples of Balhae's Unique Cultural Identity