A side-emitting light-emitting element and a packaging lens thereof, wherein the packaging lens comprises an incident surface, a reflective surface, a first refractive surface, and a second refractive surface. The first refractive surface has zigzag surfaces. After a light from a light source enters into the packaging lens through the incident surface, a portion of the light is reflected by the reflective surface to the first refractive surface via total internal reflection to vertically penetrate the first refractive surface and then proceeds along a first optical path. The other portion of the light is refracted by the second refractive surface to penetrate the second refractive surface and then proceeds along a second optical path, which is parallel to the first optical path. A zigzag surface of the first refractive surface avoids from undesired lights reflected by the first refractive surface.