Chanting "Power to the people!" and "Build a democratic China," the marchers tried to push their way through with little success.
Leung Kwok-hung, a politician, vowed to demand democracy for Hong Kong and an apology from Hu for the bloody 1989 Tiananmen crackdown and said: "I am not sure how many slogans I can shout out before security guards pull me away."
Tight security has been put in place for Hu's stay, with the Chinese leader expected to face further protests from pro-democracy activists and the Falun Gong spiritual group on Sunday.
Speaking to reporters after his arrival Hu praised the way the city had weathered an often troubled decade to celebrate the anniversary with its economy in strong form.
"I feel sincerely happy about the achievements of Hong Kong in the 10 years since returning to the motherland, and even more full of confidence in Hong Kong's future," Hu said.
The two giant pandas are the latest gifts
from China to Hong Kong [AFP]
Hong Kong's economy was hit by the Asian financial crisis that began a day after the handover on July 1, 1997.
It suffered again in 2003 when the outbreak of severe acute respiratory syndrome, or SARS, killed nearly 300 people and virtually shut down the city's vital tourist industry.
The past decade has seen the Hong Kong economy become increasingly reliant on the mainland.
On Friday the two sides agreed to consolidate a 2004 trade pact, known as the Closer Economic Partnership Agreement (CEPA) that has reduced tariffs and given Hong Kong companies freer access to mainland markets.
But critics say problems like air pollution and the rich-poor gap have worsened.
Other are angry at what they say is Beijing's heavy-handed management of political change in the territory, despite popular support for democracy.
Hu is likely to be followed during his visit by protests of pro-democracy activists and members of the Falun Gong spiritual movement, which is banned on the mainland and branded as an "evil cult" but remains legal in Hong Kong.
Falun Gong says the Hong Kong government has blocked more than 140 Taiwanese practitioners from entering the city in the days ahead of the handover anniversary.
Hong Kong's immigration department has declined to comment specifically, but says it reserves the right to decide who can enter the city.
Pro-democracy legislators and other activists plan a protest march on Sunday with one organiser saying up to 60,000 people could turn out.
Meanwhile giant pandas Le Le and Ying Ying were unveiled in a formal ceremony by Tang Jiaxuan , the Chinese state councillor.
Officials said the 22-month-old pandas, Le Le and Ying Ying, were adapting well in their new home and the public will be able to have their first glimpse of the bears on Sunday.