BEIJING, Saturday, April 9 - Several thousand young Chinese marched through Beijing's high-tech district on Saturday morning calling for a boycott of Japanese-made goods, a rare legal protest that underscored the sharp deterioration in relations between Asia's two most powerful countries.

The mostly college-age Chinese, singing China's national anthem and shouting, "Support the Chinese motherland, boycott Japanese goods," appeared to number in the thousands, but there were no official estimates on Saturday morning. The police formed a cordon around the marchers and lined every street along the parade route, but the protest had been authorized in advance and the atmosphere remained relaxed.

China's government almost never allows public demonstrations, but officials made an exception to allow people to express their anger at Japan after a series of political and territorial disputes between the two countries generated widespread popular outrage.

"Every Chinese feels anger at the way Japan ignores its own history and tries to occupy China's sovereign territory," said Li Hongbo, 19, student at Tsinghua University who participated in the demonstration. "The Japanese government must understand that China is not a weak country now. We will stand up and defend ourselves." Mr. Li wore a gray sweatshirt on which he wrote, "Little Japan, get off our land."