Abstract: With the dramatic development of semiconductor industry and the pressing need of environment protection, LED has acted as a new energy source to be applied to lighting industry. This paper selected several typical kinds of LED street lamps as the research objects which have different shapes in their respective light distribution curves. By using the light designing software Dialux，this paper simulated the LED street lamps- illuminance distribution on the road and made an analytic comparison between two different street lamps-array methods, then summed up the features of LED-s light distribution curve which were suitable for roadway lighting to provide reference for the design of LED luminaries.