Abstract: The paper aims to grasp the change law of winter wheat development period in Longdong area, and provides reference significance for phenological prediction of Loess Plateau. Based on the data of winter sunshine duration and winter wheat growth period from 1981 to 2017 in Qingyang agricultural test station, the change rule of winter sunshine duration and its influence on winter wheat growth period were studied.The results showed that the maximum value of sunshine duration in winter was 677.7h in 1999, 22% more than the usual value, and the minimum value was 426.7h in 1989, 23% less than the usual value.On the whole, the hours of sunshine in winter was less in 1980, more in 1990s, and from 2001 to 2017 is mostly less.There was a anti-correlation between winter sunshine hours and the developmental period of winter wheat in Qingyang. The most significant period of anti-correlation was the reviving, the correlation coefficient was -0.54, followed by the milk-ripe stage, the correlation coefficient was -0.44,and the third was the heading stage,the correlation coefficient was -0.42. The correlation coefficient between flowering and jointing stage was -0.4~-0.41.The most significant difference in the average development period of winter wheat between the year with the most and the least sunshine hours in winter was the erecting stage, the former was 7 days ahead of the latter.Next is the reviving, and milk-ripe stage, 6 days in advance, followed was the jointing period and mature period, 3~4 days in advance.