China is furious over the UK Navy's "plans to deploy a warship in disputed seas".
The Royal Navy has been tipped to send the HMS Queen Elizabeth to the South China Sea amid growing fears over China's surging military might in the region.
The country says it will take action to "safeguard its sovereignty, security and development interest as well as peace and stability in the South China Sea".
China's defence ministry spokesman Tan Kefei told a press conference: "The Chinese side believes that the South China Sea should not become a sea of great power rivalry dominated by weapons and warships.
"The real source of militarisation in the South China Sea comes from countries outside this region sending their warships thousands of kilometres from home to flex muscles.
"The Chinese military will take necessary measures to safeguard its sovereignty, security and development interest as well as peace and stability in the South China Sea.
"China's defence build-up and development has always been an addition to the global force for peace. We hope various parties can correct their prejudice and have a rational view of China and its military development."
The South China Sea is one of the most disputed waters on Earth.
It has been at the centre of an international row over navigational rights with Beijing.
The world's most populated country lays claims to almost all of the region, which is about 14 times the size of the the UK and stretches from Malaysia to the Philippines and from Vietnam to the edge of Indonesia.
But the international community has refuted this, insisting that China is breaching international law.
Mr Tan criticised a recent report that called for the transatlantic security alliance's 30 member countries to focus more on "security challenges" posed by China.
He said: "China opposes the baseless speculation and false accusation in the report and its defence policy remains defensive in nature."
"China’s defence build-up and development has always been an addition to the global force for peace."
The HMS Queen Elizabeth is the biggest warship ever built by the Royal Navy. It was commissioned for service in 2017 and is expected to be deployed in the South China Sea for its first operational mission.