This is not surprising that China

GDP in 2014 has become the largest in the world given its ~60% of the GDP comprises of manufacture and agriculture sectors, i.e. 6 trillion dollars, based on currency exchange ($1 = 6.2 RMB). This would result in the total GDP of China this year would be $30 trillions, almost 2 times of the USA GDP, by using the estimate of GDP in total equals 5 times of the physical GDP of a nation.