A Chinese delegation travelled to Oslo around two weeks ago to discuss the potential project, reports Sveriges Radio Ekot.
"We have discussed how China can, potentially, assist with financing and with expansion capacity and competencies," Alf S Johansen of the Värmland-Østfold Border Committee, which is coordinating the project, told Ekot.
One of the potential projects involves rebuilding and refining existing rail lines at a cost of over 50 billion kronor (5.1 billion euros). A second possibility would see an entirely new high-speed railway built at a cost of around 170 billion kronor (17.3 billion euros).
According to estimates, the high-speed connection could cut travelling time between the two Scandinavian capitals from just over five hours to less than three.
The service would reportedly be aimed at travellers who currently choose to fly between the two cities.
"This is a profitable project on which money would be earned after a few years," Johansen said.
A Chinese business delegation from the China Association for Promoting International Economic & Technical Cooperation visited Oslo in mid-January.