On the first full day of his state visit to Japan, the Chinese President Hu Jintao is holding talks with the Japanese PM, Yasuo Fukuda.
The two men are expected to sign an agreement setting out the principles for relations between their governments and another on tackling global warming.
This is only the second state visit to Japan by a Chinese leader.
Relations between China and Japan are said to be improving, after a difficult period over the past decade.
Before Wednesday's summit, Mr Hu was greeted by Japan's Emperor Akihito in a state ceremony.
Earlier Mr Hu said he hoped his visit would enhance friendship between the two nations.
"We stand at a new starting point. We must develop our strategic partnership," he said.
Difficult issues
The BBC's Chris Hogg in Tokyo says China is expected to say it will consider measures to help meet Japan's proposal to halve the world's greenhouse gas emissions by 2050.
He says they will also touch on more difficult issues, such as a row over gas and oil exploration rights in the sea between their two countries, and a dispute over food poisoning cases caused by Chinese dumplings.
Tibet is another difficult issue for the two sides, but our correspondent says the Japanese are unlikely to make any public statement on Tibet that would embarrass their visitor.
To set a friendly note, Mr Hu and Mr Fukuda are also expected to play each other in a game of ping pong. China suspended high-level contact with Japan from 2001 to 2006 during the premiership of Junichiro Koizumi, who made repeated visits to the Yasukuni war shrine, a place most Chinese believe glorifies militarism.
Mr Fukuda has tried to repair the damage by promising not to visit the shrine while he is in power and by calling for Japan to be humble about its past.
For his part, Mr Hu is reported to have agreed to loan Japan a pair of pandas to help to find a replacement for Ling Ling, a 22-year-old panda who died last week of heart failure at a Tokyo zoo.
The BBC's Chris Hogg says it is in the interest of each country to get along better with its near neighbour.
China wants Japanese technology and investment to help develop its economy further, while Japan wants to sell more of its products to the Chinese, particularly as demand in other important markets like the United States slows, our correspondent says.
China has overtaken the US as Japan's top trading partner, with bilateral trade increasing 12% last year to $236.6bn.
