Electron electron correlation is more significant in negative ions than neutral atoms, often dominating the atomic structure of the ion and the cross section for interaction with an extrenal field. The negative carbon ion (2s 22p 3) and (2s 12p 4) levels, wavelength, radiative lifetime and photodetachment are discussed. The double states (1s 22s 12p 4) of negative carbon ion are more steady than its quartet states. The wavelength between (2s 22p 3) and (2s 12p 4) is located near XUV and 6 strong wavelengths are given. It can offer material for X ray laser.