A method for manufacturing a white light source includes steps of providing an ultra-violet light as a radiation source, preparing three kinds of first phosphors each receiving the ultra-violet light and emitting the light of red, green and blue, respectively, and preparing at least one additional second phosphor to modify a spectral property of the light emitted by the three first phosphors in order to improve the brightness and color rendering property of the white light source. Moreover, at least one phosphor with the fluorescent property is used as the above second phosphor powder to obtain a color-changeable light source.