Liang Wengen, the chairman of Sany Heavy Industry, has again been crowned was crowned China's richest man for the second time in a week as a mainland construction boom helped raise his personal net worth to US$9.3 billion. The number of US dollar mainland billionaires increased to 146 from 128 last year despite a weak stock market, according to the annual Forbes China rich list released yesterday. Liang, 55, moved up two notches from third richest mainlander last year as his wealth grew from US$5.9 billion to US$9.3 billion. He only just edged out Wahaha Group boss Zong Qinghou by a few million dollars, with Robin Li Yanhong, chairman of internet search engine Baidu third on US$9.2 billion. On Wednesday, the Hurun Rich List 2011 also gave Liang the top spot with a fortune valued at 70 billion yuan (HK$85.3 billion). 'The rise of Sany reflected China's soaring spending on infrastructure construction,' Forbes said in a statement. 'The increasing investment in infrastructure brought huge benefits to heavy machinery makers.' Sany also plans to list on the Hong Kong stock exchange, a move that could further boost Liang's fortune. The mainland's infrastructure package in the past two years ushered in a construction boom in the world's second-largest economy, bringing a windfall to Liang and his businesses. Sany reported net profits of 5.9 billion yuan in the first half of this year, more than double the figure a year ago. Three managers at Sany - Tang Xiuguo, Mao Zhongwu and Xiang Wenbo - were also among the top 100 richest mainlanders, according to Forbes. In the Hurun report, the mainland has 271 billionaires in dollar terms, up from 189 last year. Factoring in the 'hidden billionaires' who were yet to be uncovered by the compilers of the riches lists, the number could hit 600, analysts said. China trailed only the United States in terms of the number of billionaires, underscoring the country's rising economic might. The top 400 richest people had a total net worth of US$459 billion, up 8 per cent from last year, according to Forbes. Both the Forbes and Hurun rich lists looked at tycoons only on the mainland. The country has the highest number of self-made billionaires worldwide thanks to the buoyant growth of privately owned businesses in the past three decades. The Hurun report said 127 mainland billionaires struck it rich with their own businesses. 'I would attribute the rising number of mainland billionaires to an entrepreneurship rarely been seen in other parts of the world,' Xiang told a press conference hosted by Forbes in Shanghai yesterday. 'We actually don't pay much attention to the wealth figures released by the rich lists. We are focused on improving the performances of our businesses.'