According to the regional GDP released on February 28 by the Census and Statistics Department of Hong Kong,Shenzhen has overtaken Hongkong for the first timeif counted at the mid-point of Hong Kong dollar /RMB yuan on that day. In fact, according to the official algorithm, it is wrong to calculate according to the exchange rate on the day, it should be calculated according to the average exchange rate in 2017. At present, Shenzhen GDP has not yet exceeded Hong Kong, but the gap between Shenzhen and Hong Kong is further narrowed. Data released by the Census and Statistics Department on the website of Hong Kong Special Administrative Region on February 28 showed that in 2017, Hong Kong achieved a GDP of 2.662637 trillion Hong Kong dollars. The actual growth is 3.8% and nominal growth is 6.9%. Some media reported according to the mid-point of the Hong Kong dollar /RMB yuan on the 28th that Hong Kong's GDP is equivalent to about 2. 215295 billion yuan. Compared with Shenzhen's recently announced GDP of 2.22439 trillion yuan in 2017, it is lower than that of Shenzhen. This concludes that Shenzhen GDP surpassed Hong Kong in 2017 for the first time and became the first city in the aggregate economy in cities inGuangdong, Hong Kong and Macao Bay Area. It is understood that it is not objective to calculate according to the exchange rate of the day (the midpoint of Hong Kong dollar / RMB). The common official calculation and comparison of Hong Kong's gross domestic product should be based on the 2017 annual average exchange rate as the correct algorithm. According to the exchange rate provided by the Hong Kong Census and Statistics Department's website, based on the average RMB exchange rate of 1.1552 against the Hong Kong dollar in 2017, Hong Kong's GDP was 2,304.914 billion yuan last year and was61.75 billion yuan more than Shenzhen. Shenzhen GDP has not yet exceeded Hong Kong. Although it is still not over, the gap between Shenzhen and Hong Kong's GDP has narrowed further. The difference narrowed by more than half over the 2016 figure and narrowed from a shortfall of $ 130.5 billion in 2016 to $ 61.1 billion in 2017.