A lighting device comprising: a first to a fourth light emitting devices which are disposed on a substrate; a first and a second pulse width modulation controllers configured to perform a pulse width modulation on currents applied to the first and the second light emitting devices respectively; a first and a second controllers configured to control respectively currents applied to the third and the fourth light emitting devices having color temperatures different from those of the first and the second light emitting devices; wherein an "x, y" coordinate, which is determined by the mixture of the lights emitted from the first to the fourth light emitting devices and is located within a 1931 CIE chromaticity diagram, is moved onto a black body radiation curve within the 1931 CIE chromaticity diagram through the pulse width modulation of the first and the second pulse width modulation controllers (200, 300) and the control of the first and the second controllers (400, 500), wherein the lighting device comprises a mixing chamber (150, 10) which receives the first to the fourth light emitting devices and has an open upper portion; and an optical excitation plate which is disposed on the mixing chamber (150, 10) and is spaced apart from the first to the fourth light emitting devices, wherein a distance between the optical excitation plate and the first to the fourth light emitting devices is determined by an optical orientation angle (θ) of each of the first to the fourth light emitting devices and a distance between the light emitting devices, characterized in that the distance between the light emitting devices among the first to the fourth light emitting devices is calculated by an equation of G = 2Htan(θ/2), color temperatures of the first and the third light emitting devices are higher than those of the second and the fourth light emitting devices, the first to the fourth light emitting devices being symmetrically disposed. a first to a fourth light emitting devices which are disposed on a substrate; a first and a second pulse width modulation controllers configured to perform a pulse width modulation on currents applied to the first and the second light emitting devices respectively; a first and a second controllers configured to control respectively currents applied to the third and the fourth light emitting devices having color temperatures different from those of the first and the second light emitting devices; wherein an "x, y" coordinate, which is determined by the mixture of the lights emitted from the first to the fourth light emitting devices and is located within a 1931 CIE chromaticity diagram, is moved onto a black body radiation curve within the 1931 CIE chromaticity diagram through the pulse width modulation of the first and the second pulse width modulation controllers (200, 300) and the control of the first and the second controllers (400, 500), wherein the lighting device comprises a mixing chamber (150, 10) which receives the first to the fourth light emitting devices and has an open upper portion; and an optical excitation plate which is disposed on the mixing chamber (150, 10) and is spaced apart from the first to the fourth light emitting devices, wherein a distance between the optical excitation plate and the first to the fourth light emitting devices is determined by an optical orientation angle (θ) of each of the first to the fourth light emitting devices and a distance between the light emitting devices, characterized in that the distance between the light emitting devices among the first to the fourth light emitting devices is calculated by an equation of G = 2Htan(θ/2), color temperatures of the first and the third light emitting devices are higher than those of the second and the fourth light emitting devices, the first to the fourth light emitting devices being symmetrically disposed.