The objective of the autofuorescence spectrum of hepatic carcinoma cell and hepatic cell studied was to understand if there was difference between the two cells. So we cultured SMMC-7721 hepatic carcinoma cell and HL-7702 hepatic cell in vitro. Then their autofuorescence was detected by fluorescent spectrograph. It presents that the spectrogram of the hepatic carcinoma cell resembles that of the hepatic cell at the range of wavelength from 550～720 nm characterized by two peaks at 602 nm and 691 nm. But from 721～800 nm, the spectra of carcinoma cell with a peak located at 734 nm were found. For the hepatic cell the peak at 734 nm was not observed. The experimentations of propagation of both cells confirm ulteriorly that there is a significant difference between two cells'spectrum. The experiment will be beneficial to the next research of detecting hepatic carcinoma by fluorescent fiber optic biosensor.