A senior Chinese civil aviation official said Thursday that China, the world's most populous nation, would build 56 more airports during the next five years to expand transport capacity. Head of the Civil Aviation Administration of China (CAAC), Li Jiaxiang,said the total number of airports in the country would likely top 230 in five years with an aircraft fleet expected to exceed 4,500 units, enough to carry 450 million passengers annually. "Investment in China's aviation industry is likely to reach 1.5 trillion yuan (about 230 billion U.S. dollars) in the next five years," Li said at a national civil-aviation work conference held in Guiyang, capital city of southwest China''s Guizhou Province, and reported by Xinhua news agency Friday. China's investment in building airports has accelerated since the turn of the century. From 2005 to 2010, 33 new airports were constructed while another 33 were renovated or expanded, bringing the total number of airports to 175 in 2010. Investment in building civil aviation infrastructure during this period hit 250 billion yuan, nearly the equivalent of total spent during the previous 25 years.