This report uses econometric methods，such as composite index and early warning signal system to monitor and predict China’s economic fluctuation，and gets the following conclusions：Since 2000，the fifth growth rate cyclein China reached its trough in November 2015，and then recovered and reached its peakin April 2017. After that，the economic climate entered the decline stage of a new growth rate cycle and lasted for 8 months until December 2017. Based on the information of the leading index，China’s economic growth is expected to be in a steady decline state in 2018. Considering the uncertainties of the current global economic recovery and supply-side structural reform，the real GDP growth rate of 2018 will fluctuate around 6.6%. Since the price growth cycle lags economic growth cycle as well as therapid increase in PPI is conductive to CPI，CPI is expected to rise slowly in 2018 which can be controlled within 3%.