Justice minister Mark Golding said possession of up to two ounces (56 grams) of ganja would result in a fine instead of an arrest, while use of the drug for religious, medical or research purposes will be made legal.
Mr Golding said convictions for smoking spliffs were too strong with youths indulging in the illegal drug later denied jobs and visas because of their record.
"A criminal conviction and the attendant significant adverse long-term consequences are not justifiable for what is a relatively minor offence," Mr Golding said.
"The changes to the law contemplated are not novel," he added. "The decriminalisation of ganja in Jamaica has been the subject of considerable study and recommendations over the years."
The proposal for decriminalisation dated back to 1977 before the nation's National Commission on Ganja stepped up support for the move in 2001.
Approval of the government changes to the Dangerous Drugs Act will see Jamaica join Uruguay and the US states Colorado and Washington in recent moves to legalise the drug under limited circumstances.
