Shipments have typically stopped in February over the last few years, and market participants were focusing on whether exports restarted as usual in March.
A continued halt may have indicated that Beijing was looking to pressure Pyongyang amid weeks of heightened hostility on the Korean peninsula. But exports over March actually rose 8.2 percent on the year, while the figure for the first quarter reached 159,002 tonnes, up 6.7 percent from the same period in 2012.
China is North Korea's only major supporter, but it has signalled its unease over Pyongyang's escalating threats in April.
Crude oil is the largest commodity by value that Beijing supplies to North Korea under an aid programme, which also includes diesel and aviation fuel.