FACTBOX-The state of China-Japan relations

April 29 - Japanese Prime Minister Taro Aso will visit China for two days from Wednesday, with the summit between Asia's two biggest economies likely to focus on the global slump.

But the two neighbours also have festering bilateral disputes and differences over North Korea that may unsettle soothing messages on economic cooperation.

Here are some facts about ties between China and Japan.

ECONOMIC POWERHOUSES

-- Japan and China are respectively the world's second- and third-biggest economies.

-- China-Japan trade grew to $266.4 billion in 2008, a rise of 12.5 percent on 2007, making China Japan's top two-way trade partner. China was also the second biggest destination for Japanese exports in 2008, after the United States, with Japanese exports to its Asian neighbour totalling $124.2 billion, up 13.8 percent.

-- But the global slowdown has slowed trade between them. Japan's exports to China in March fell 31.5 percent from a year earlier, a smaller fall than in January and February.

-- Aso is likely to raise food safety at the summit, as public worries have slowed Japan's food purchases from China. Frozen dumplings from China made several Japanese sick in 2008, sparking accusations the dumplings had been deliberately poisoned.

HISTORICAL TENSIONS

-- Japan invaded and occupied much of China from 1931 to 1945, and rancour over wartime memories continues to shape Chinese public attitudes. Memories of Japanese atrocities run deep, especially the Nanjing massacre of 1937, when China says Japanese troops killed 300,000 people in what was then the national capital. A postwar Allied tribunal put the death toll at 142,000, while some conservative Japanese politicians and scholars deny a massacre took place.

-- China and other Asian countries are critical of Tokyo's Yasukuni Shrine for war dead, which they call a symbol of past militarism. Among some 2.5 million souls honoured in the Shinto shrine are 14 Class A war criminals convicted by the Allied tribunal after World War Two.

-- Aso has not visited Yasukuni while prime minister, but Beijing last week said it was angry after it was revealed that Aso had sent a potted tree as a ritual offering to the shrine.

TAIWAN, NORTH KOREA

-- China is always eager for Japanese to clearly back Beijing's "one China" stance on Taiwan, the self-ruled island China wants to accept eventual unification. Japan says it accepts "one China", but many Japanese politicians and businesses have close ties with Taiwan, which was a Japanese colony between 1895 and 1945.

-- China and Japan are both in six-party talks aiming to halt North Korea's nuclear ambitions. But Pyongyang's recent long-range rocket launch has laid bare differences in their views of Pyongyang. Tokyo condemned the launch, which it said was a missile test, and pressed for a U.N. Security Council resolution. China has urged patience and resisted the proposed resolution, arguing that confrontation will not draw Pyongyang back to talks.

EAST CHINA SEA DISPUTE

-- China and Japan have been at odds over China's exploration for natural gas in the East China Sea. In June last year they reached a broad agreement on principles intended to solve the dispute by jointly developing gas fields. But progress has been slow, and Japan has accused China of drilling for gas in violation of the agreement.

-- Japan says the median line between the two countries' coasts marks the boundary between their exclusive economic zones. China says the boundary is defined by its continental shelf, extending its zone beyond the median line.

-- Tokyo objects to Chinese development of the Chunxiao gas field in seas close to Japan's claimed boundary. Japan fears drilling there could drain gas from what it claims is its side of the line through a honeycomb of seabed rocks.

-- Both Tokyo and Beijing claim sovereignty over a group of islets, known as Senkaku in Japan and Diaoyu in China, in the East China Sea. (Sources: Reuters; Japan External Trade Organisation http://www.jetro.go.jp; Selig Harrison (ed.), Seabed Petroleum in Northeast Asia)