Fu Ying, spokeswoman for China's annual parliament session the National People's Congress (NPC), gave the "rough" figure and said it was in line with overall spending growth.
A formal announcement will be made on Thursday when the NPC opens.
China has seen several years of double-digit defence spending increases. It is the world's second-highest military spender, but remains far behind the US.
Last year, China's defence spending rose 12.2% to $130bn (Â£85bn). In comparison, for the fiscal year 2016 US President Barack Obama has requested a budget of $585bn.
China says the spending is required to modernise the People's Liberation Army - the world's largest standing military.
It is pouring investment into hi-tech equipment such as submarines and stealth jets, reports the BBC's Martin Patience in Beijing.
It has also been investing in naval forces, including an aircraft carrier. Recent media reports that a second was being built were swiftly deleted.
China's neighbours are closely watching its military investment.
In recent years Beijing has taken a more assertive stance on maritime territorial disputes with both Japan and South East Asian nations, leading to a rise in regional tensions.
In response, Japan has begun increasing its military budget, as has India - which has a disputed land border with China.
US officials also fear that China understates its current military spending, suspecting the real figure could be considerably higher.
Ms Fu said China had not forgotten lessons from history - "those who fall behind will get bullied".
"Our country will achieve modernisation, of which national defence modernisation is an important part," she added. "This requires a certain guaranteed amount of funding."
China's military budget will rise by about 10% in 2015, an official says.