A new Chemiluminescence cell for flow injection analysis was designed and tried on main common Chemiluminescence reaction . The cell design consist of two compartment mechanically separated completely except that light energy released in the first compartment is transferred via an optical fiber (7 mm ) for a maximum distance 35 cm . This new design takes into account that reaction and receiving signal is done away from the processing of signal by a PMT supplied by high voltage in the second compartment . The exact calculated cell volume is 75.36 µl ( 4mm diameter with 6 mm length ( volume of cylinder ) poly metha methyl acrylate. (PMMA) was used for manufacturing both compartments . The seeing point of optical fiber is 4 mm away from reaction junction ( i. e no direct contact between reaction Solutions and the optical fiber ). The whole design was tested for luminol – H2O2 – Co(II) and luminol – folic acid – OH- . Signal- Noise – Ratio (S/N) was achieved using a RC- Law band pass electron filter of time constant of 1.438 seconds. A relative standard deviation of less than 1% was the usual pattern of normal working procedure for determination of H2O2 ( r2 % = 0.9696% ) for 0.1- 15 µM , while for folic acid  r2 % = 0.9745% for 1- 50  µM .