The conventional glutaraldehyde (GA) fixation method of tissue valves is considered to be responsible for accelerated valve degeneration. The release of toxic GA from the valve tissue is believed to limit endothelial cell (EC) ingrowth. Removal of toxic GA by reaction with L-glutamic acid and storage in a Paraben solution may offer good EC growth. To investigate the conditions for endothelialization of tissue valves, the growth properties of ECs on the conventionally and alternatively treated pericardial tissue were compared. Conventional preparation included zero-pressure fixation for 72 hours in phosphated-buffered saline (PBS) solution containing 0.5% GA at 4$^{circ}C$ and storage into PBS containing 0.2% GA(group I). Alternatively treated pericardial tissues were divided into three postfixation treatment groups : (1) storage in PBS solution containing Paraben(group II), (2) treatment with PBS containing 8$^{circ}C$ L-glutamic acid(PH 7.35) and storage in PBS solution containing Paraben (g oup III), (3) treatment with L-glutamic acid dissolved in distilled water (PH 3.5) (group IV). Pericardial tissue were transferred into the 24-well plate after storage for 4 weeks. ECs were harvested enzymatically from the bovine pulmonary artery and grown to confluence on culture flask surfaces. Detached ECs by trypsin were incubated into the each well of the 24-well plate including test pericardial tissues. Cells were detached by trypsin, 1, 2, 3, 5, 7 days after incubation and counted on the hemacytometer. Cell viability test was performed by frypan-blue exclusion method. Acute cell death in the group I were found even after prolonged washing. The group II showed prolonged cell survival compared with the group I. Both group III and group IV showed better cell growth than group II. There was no statistically significant difference between group III and group IV method in terms of EC growth. This results suggest that treatment by L-glutamic ac id and storage in a Paraben solution be a promising approach for improvement of durability of GA-treated tissue valves.