The research work on the photoemission in CdS crystal was mostly limited in the behavior of bound exciton

excitonic molecule and exciton-exciton (E

x

-E

x

) interaction at rather lower temperature

[1-3]

. Saito et al.

[3]

studied the emission of the near-band edge in CdS within 8-65K. We have investigated exciton-carrier (E

x

-e) interaction and the annihilation of a free exciton with emission of a photon and one-LO or two-LO phonons utilizing the photo luminescence (PL) and electroluminescence (EL)

[5]

. Up to now

there has been no report on E

x

-E

x

interaction in CdS crystal at the temperature higher than 80K.This paper mainly studies the behavior of E

x

-E

x

E

x

-e

E

x

-1LO and E

x

-2LO interaction and the stimulated emission due to E

x

-E

x

interaction in CdS.The CdS crystal used in this experiment was grown by sublimation method in our laboratory.The PL spectra were measured by Model 44W spectrometer with a RCA C31034 photomultiplier at the excitation of 337.1nm line of a N

2

laser in the temperature range of 77K-RT.Fig.