A polarized semiconductor light emitting device includes a semiconductor structure having a first conductivity semiconductor layer, an active layer and a second conductivity semiconductor layer sequentially stacked. Also, the semiconductor structure further includes a plurality of light guide parts defined by a plurality of grooves arranged along a predetermined direction. The grooves extend from the second conductivity semiconductor layer with a depth reaching at least the active layer, and the light guide parts have a length greater than a width thereof to selectively emit a polarized component in a length direction thereof.