The killing occurred during an attempt by South Korean maritime authorities to board a Chinese fishing vessel suspected of illegally fishing in South Korean waters in the Yellow Sea west of Seoul.
The Incheon District Court also fined the captain, Cheng Dawei, 43, nearly $17,600 for the killing, which had reignited public anger at Chinese fishermen's use of violence against South Korean coast guard officers, a report by South Korea's Yonhap news agency said.
Cheng was charged with killing coast guard Cpl. Lee Cheong-ho and seriously injuring an officer.
Immediately after the incident, South Korean President Lee Myung-bak called for "strong" measures to protect the country's coast guard sailors who are cracking down on illegal fishing by Chinese boats.
The court sentenced eight other Chinese fishermen from the same vessel to prison terms ranging from 1 1/2 years to five years for obstructing coast guard officers, Yonhap said.
"One officer's loss of life and another's serious injury brought shock, sadness and anger not only to the families but also the entire nation," the court said in its ruling.
"A firm call to responsibility is unavoidable if only to prevent a repeat of other illegal activities and more tragedies they could lead to."
Last year the coast guard said it captured or sent back more than 470 Chinese fishing boats that were suspected of illegally fishing for vessels last year which were suspected of illegally fishing for anchovies, blue crabs and croakers.
Last year's fatal incident comes after several other deaths during incidents involving Chinese fishing boats and South Korean coast guard ships.
Seoul and Beijing, which have been working to avoid clashes over fishing, signed an accord last week.
Urgency to reach the agreement, which was reached in Qingdao, China, was heightened by December's incident, Yonhap reported.
The accord included an agreement Chinese boats will record fishing logs using Global Positioning System technology while fishing near South Korea's exclusive economic zone.
Other deaths also have occurred in the past several years.
In September 2008, The Korea Times reported a coast guard officer allegedly was beaten to death by Chinese fishermen during as South Korean maritime authorities attempted to board a Chinese vessel.
The body of the 48-year-old officer was found in the sea the following day near the southwest port of Mokpo City, The Korea Times said.
An incident in December 2010 left on Chinese fisherman dead and two missing after their boat capsized.
One of 50 or more Chinese boats intentionally rammed what was a larger coast guard ship in what appeared to be a bid to allow other ships to escape.
Eight people from the capsized boat were pulled from the sea but one was unconscious and later died in a hospital, the coast guard office said in a statement at the time.
Chinese fishermen allegedly attacked coast guard officials with steel pipes, shovels and clubs to stop being boarded.
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