The $1 million Hong Kong float for the Golden Jubilee parade in Beijing was branded a disappointment.
Legislator Lau Kong-wah, a member of the 200-strong SAR delegation, said the float did not match up to those for Macau and Taiwan.
'I can't find out what theme or message the SAR wanted to convey,' he said after the parade in Tiananmen Square.
Mr Lau, of the Democratic Alliance for the Betterment of Hong Kong, said many other delegates were also disappointed.
'It was not made just for the Hong Kong audience, but for all the people on the mainland. Everyone is looking at us. Why was it so bad?' he asked.
The float, with the Chinese characters for Hong Kong as drawn by President Jiang on its front, was designed as an express train carrying infrastructure landmarks such as the Tsing Ma Bridge and the Bank of China Tower.