A light emitting device includes an epitaxial structure. The epitaxial structure includes a first type semiconductor layer, a second type semiconductor layer and a light emitting layer. The first type semiconductor layer includes a first semiconductor sublayer. The light emitting layer is disposed between the first type semiconductor layer and the second type semiconductor layer. The first semiconductor sublayer includes a heavily doped part and a lightly doped part which are doped by a first type dopant. A doping concentration of the first type dopant in the heavily doped part is equal to 1018 atoms/cm3 or between 1017 atoms/cm3 and 1018 atoms/cm3. A doping concentration of the first type dopant in the lightly doped part is less than or equal to 1017 atoms/cm3.