Huang Qi, 56, is the founder of 64 Tianwang - the first human rights monitoring website in the country - which documents enforced disappearances and human trafficking. It has also served as a platform for dissident voices.
The Intermediate People's Court of the central city of Mianyang announced the sentence on its website, adding that Huang will also be deprived of political rights for four years and that it imposed a 20,000-yuan ($2,900) fine.
Activist and journalist Huang has been arrested many times and served jail terms in reprisal for his work.
Human rights non-profit Amnesty International criticized the fact that the activist's family had not been informed of the verdict, Efe news reported.
In the past, Amnesty and other human rights groups have alleged that Huang has been tortured during his time in custody, a common complaint by activists, journalists and human rights lawyers who have stayed in Chinese detention centres.
In December, the UN urged the Chinese government to "release Huang immediately ... in accordance with international law," due to the deteriorating state of his health.
According to UN human rights experts, Huang suffers from "high blood pressure, heart disease, chronic kidney condition and hydrocephalus".
"Without the required medical treatment, Huang's health may continue to deteriorate to a fatal point," said the experts.
( With inputs from IANS )