Shanghai is the largest industrial and commercial center and the most rapidly growing city in China In order to approach Shanghai urban in fluence on the solar radiation, we deal with the following two aspects:1. Evolution of annual solar radiation during the last 28 years in Shanghai area (1958-1985). From the late 1960s’, the direct solar radiation (S) in Shanghai central observatory obviously decreased while the diffuse solar radition(D) increased gradually. Since the decrement of S is greater than the increment of D, the global radistion (Q + S + D) had the ?oine decreased trend as S. But these trends did not appear in Shanghai rural areas. The results obtained from the spectral analysis show that the decreased or increased trends of S, Q and D in city are closely related to the consumption of coal and the amount of fall dust in the urban district.2. The difference of solar radiation between Shanghai city and its suburban counties. By using the simultaneous observational data of percentage of possible sunshine and amount of clouds in Shanghai city and its subrubs, we calculated the values of S. D, and Q for its nearby ten rural stations (applying suitable statistical formula). The results show that the urban district has the lowest values of S. and Q. In view of the turbidity factor (D/S), the urban district gives the highest value. The effect of turbidity- island’ is obvious.