Abstract: The rights of "sharing the sun light" of citizens has gained more emphasis than ever before with the development of the metropolitan.A theoretical formula is presented for calculating the sun's angle at sunrise and sunset with the divert headings of the streets and the different ratio of length to height combined with the period from the Vernal Equinox to the Autumnal Equinox and vice versa in Ziyang City.It has been point out that the east-to-west orientation of the streets is far superior to any other orientation, and that the proper ratios (L/H) is needed for better sunshine.Using last five years actual hours to the sun and the observed materials proposed for the implementing of statistics analysis, it has been pointed out that in Ziyang city, the amount of the clouds has overwhelming impact on the time in getting sunlight.