The trip comes about a week after US President Donald Trump held talks with his Chinese counterpart, Xi Jinping, in Beijing as part of his 5-nation tour of Asia and said they agreed to "increase economic pressure until North Korea abandons its reckless and unsafe path".
China has previously pushed for a diplomatic solution to the crisis over North Korea; however, Pyongyang has so far ignored Beijing's calls to end its nuclear and ballistic missile programs and return to the negotiating table.
Song's trip came amid strained relations between China and North Korea over Pyongyang's nuclear and missile programs.
"Comrade General Secretary of the Communist Party of China Xi Jinping's special envoy, Comrade Song Tao, and his delegation have paid respects at Kumsusan Palace of the Sun" on Sunday, the Korean Central News Agency (KCNA) reported.
CHINA has dispatched a special envoy to North Korea for the first time in years in a bid to curb tyrant Kim Jong-un's growing ambition of becoming a nuclear power.
Trump toned down his fire and brimstone rhetoric toward Pyongyang in recent weeks, and North Korea has not conducted any ballistic missile launches over the past two months.
China, which has so far played down Song's visit, remains cautious not to expect any major breakthrough from the trip. They exchanged views about the situation on the Korean Peninsula and in the region and on bilateral relations, the KCNA said. It is still unclear whether Song will hold direct talks with Kim during this trip.
Since taking office after the death of his father, late leader Kim Jong-il, in December 2011, Kim has yet to meet Chinese President Xi.
China's Global Times called for caution for high anticipation, saying that whether North Korea's nuclear issue can be resolved depends on Washington and Pyongyang's political resolve.
Song also traveled to Hoechang County, west of Pyongyang, to tour what was Chinese military forces' headquarters during the 1950-53 Korean War, it also said. "The key to easing the situation in the peninsula lies in the hands of Washington and Pyongyang. If both sides insist on their own logic and refuse to move in the same direction, even if Song opens a door for talks, the door could be closed anytime", the newspaper said in an editorial. Perhaps the lowest point since the Korean War.
He continued, "If they stop their shooting missiles, stop developing nukes, stop building more nukes, we can talk".
The visit, whose length and content have not been specified in reports, is the first by a high-ranking Chinese official to North Korea in more than a year.
China's Foreign Ministry responded that its "suspension for suspension" initiative is the most "reasonable proposal" to ease tensions.