The drugs were found in the Mallusk area on Wednesday.
A 33-year-old man was arrested during the PSNI Organised Crime Branch operation.
He remains in police custody.
Meanwhile a 37-year-old man has been arrested following the seizure of £50,000 worth of cannabis from a house in the Bracken Grove area of Newry.
He is being questioned on suspicion of a number of offences including cultivating cannabis, possession of a class B drug and possession of a class B drug with intent to supply.
Newry and Mourne Area Commander, Chief Inspector Davy Beck, said: "My officers are committed to detecting and prosecuting drug dealers and taking dangerous drugs off our streets.
"We remain dedicated to carrying out proactive searches against drug dealers."