This might be the latest stop by the North's ruler Kim Jong-il as he seeks to shore up ties with the country's sole major supporter, reports Reuters.
This is a secret visit from North Korea while China's premier Wen Jiabao is visiting Japan for a summit with his counterparts of Japan and South Korea.
North Korea shook the Southern region last year with its aggressive stance towards the richer South, and has close ties with Beijing for its economic and diplomatic support.
Neither Pyongyang nor Beijing has said whether he or his son and heir apparent Kim Jong-un, will be visiting China, since they are secretive about such trips.
But tight security and unscheduled train movements echoed past visits by 69-year-old Kim Jong-il, who visited twice last year to lure its neighboring country.
China is going to steady its ties with Seoul and Tokyo, but also sees North Korea as a strategic against the United States and its regional allies.
On Saturday morning, the train reached Changchun, the capital of Jilin province of China where the exit was cordoned off by the police.
In the past, such visits have also been secret-- China and North Korea have acknowledged a visit only after it has ended or about to end.
During Jong-il's earlier trips, he had told Hu that Pyongyang remained committed to stopping the nuclear facilities according to the previous international agreements.
This announcement shows that N. Korea is not serious about its push to restart aid for the disarmament of its nuclear talks, which have been stalled for more than two years, said the report.