The China National Intellectural Property Adminitrtion (CNIPA) recently announced the termination of the bilateral exchange of electronic priority documents between China and South Korea, which had came into use since January 1, 2014 according to No. 196 Announcement of CNIPA.
As agreed by both China and South Korea, the bilateral exchange of electronic priority documents shall be available on WIPO DAS platform. The applicants that file applications after January 1, 2021 shall follow the instructions of WIPO DAS platform for the request for electronic priority documents. More details can be found through WIPO website: http://www.wipo.int/das/en/.
(Source: CNIPA website)