Lu Wenfeng showed up with the bomb at the ceremony Saturday in Jixian county, Heilongjiang province, and set it off "out of his resentment for his ex-wife," the official Xinhua News Agency said. No other details were given.
Xinhua did not say if Lu's ex-wife or new husband were among the victims. Eight people, including Lu, were killed at the scene, Xinhua said. Another six were injured and one later died at the hospital, it said.
Lu and Li Jinling divorced in 2005 after five years of marriage, Xinhua said.
Explosives are readily available in China for mining and construction. Bombs are frequently used in attacks stemming from personal feuds or business disputes.