The characteristics of ALA absorption spectra under different conditions are studied with spectrometers. The results indicate that the wavelength of ALA,corresponding to the strongest absorption peak, is 282 nm under different conditions. The content of PplX synthesized is in direct proportion to the density of Jurkat cells. The most suitable culture time is 8 hours in order to synthesize more PplX. FCS has a block effect on the synthesis of PpIX.