In this paper I review both the history of solar observations in ancient China and recent researches on solar variability. The paper consists of three parts. In the first part I describe Sun worship and the early observations of solar phenomena. In the second part I concentrate on sunspot observations and improving the catalogue of naked-eye sunspot records. In the third part I discuss long-term variations of solar activity by using historical sunspot records over 2000 years. The 210-year cycle, which has the largest significance in the power spectrum, may have an important influence on the forecasting of the next cycle (no. 22).