Anti-Japanese protests have been building throughout the week
The rallies follow a 10,000-strong march in the Chinese capital - the city's biggest protest since 1999.
Protesters are angry at a new Japanese history textbook which they believe plays down Japan's wartime atrocities.
Japan has protested to China after stone-throwing protesters attacked Japan's embassy in Beijing on Saturday.
Japan's foreign minister is to visit China next week to discuss "a number of bilateral and international issues", a spokesman for Japan's Foreign Ministry said.
Security measures
At least 3,000 people demonstrated at the Japanese consulate in the southern city of Guangzhou on Sunday, shouting for a boycott of Japanese goods and burning Japanese flags.
A Japanese diplomat said some windows in the consulate were broken.
Hong Kong cable television showed protesters with Chinese flags and banners reading "down with Japanese militarism".
A city hall spokesman said the "spontaneous demonstration" was peaceful and under control.
China says it has mobilised a huge police force to maintain order.
Thousands more marched in Shenzhen, also in the southern Guangdong province, and threw objects at Japanese-owned businesses.
On Saturday, Japan summoned the Chinese ambassador to demand a formal apology, after windows at its embassy in Beijing were broken during a demonstration, despite the presence of Chinese police.
The ambassador, Wang Yi, said Beijing did not condone the protests.
However, correspondents say the fact that Saturday's demonstration took place at all signals tacit acceptance, if not approval, by the authorities.
'Whitewash'
The protests were sparked by new Japanese schoolbooks, which many Chinese say whitewash Japan's occupation of much of China during the 1930s and early 1940s.
Critics are angered that one of the books refers to the killing of more than 250,000 civilians by Japanese troops in the Chinese city of Nanjing in 1937 as an "incident", rather than the "massacre" it is known as elsewhere.
China says it mobilised police to protect Japanese buildings
They also say it glosses over mass sex slavery of Asian women by Japanese troops.
Anti-Japanese sentiment has also been fuelled by Japan's campaign for a permanent seat on the UN Security Council.
Many Chinese feel Japan has not yet addressed its wartime history, and as such is not fit to take up such a position of responsibility, says the BBC's Rupert Wingfield-Hayes in Beijing.
Tokyo says private companies, not the government, were responsible for the texts, and that it is up to individual school districts to decide which books they use.
The book, approved by a local education authority, is one of many and has been taken up by a tiny proportion of schools in Japan, our correspondent says.
The protesters repeated their demands for a boycott of Japanese goods, to block Japan from obtaining a seat on the U.N. Security Council, and for Japan to change textbooks which they say whitewash Japan's war atrocities.
Chinese protests against the publication of a Japanese government textbook continued for a second day in China, (Sunday) as an estimated three thousand protesters marched on the Japanese consulate in Guangzhou. Thousands of protesters also marched in Shenzhen, throwing objects at Japanese businesses.

The protesters repeated their demands for a boycott of Japanese goods, to block Japan from obtaining a seat on the U.N. Security Council, and for Japan to change textbooks which they say whitewash Japan's war atrocities. Protesters burned Japanese flags while singing and shouting anti-Japanese slogans. They also carried anti-Japanese signs along with Chinese flags.
Chinese view the textbook as "whitewashing" the events and actions of Japan to cast them in a more positive light. 

The protests are against the , which is publishing a high-school textbook that refers to the Nanjing Massacre as an "incident" ( translation) and de-emphasizes the roles of comfort women as well as the contemporary issues surrounding Japanese Prime Minister Junichiro Koizumi's visits to the Yasukuni shrine, in honor of Japanese soldiers. 

The Japanese government has claimed that the demonstrations have an "anti-Japanese sentiment," for which China should apologise.
In , Japan formally summoned Wang Yi, China's ambassador to Japan, concerning China's actions on Sunday.

"We formally demanded China’s apology and compensation," said Japanese Foreign Minister . He also said that Wang Yi replied "No" when asked for an apology.

While not issuing a formal apology through diplomatic channels, Wang claimed that China did not approve of the violent aspects of the protests.

"The (Chinese) government does not agree with extreme action," he said.

Back in , the ''People's Daily'' reported that Chinese Foreign Ministry spokesman Qin Gang deflected blame away from China for the recent downturn in Sino-Japanese relations.

"Japan must adopt an earnest attitude and appropriate ways to deal with major principled issues concerning the feelings of the Chinese people," Qin said. "The Japanese have to do more things conducive to enhancing mutual trust and maintaining the relations between the two countries, rather than doing the reverse," he said.