In order to develop a molded collagen sheath for ear surgery, autologous temporal muscle fascia treated with chemical preservative was chosen. Human temporal muscle fascias were taken, molded, dried and treated with buffered glutaraldehyde, formaldehyde and alcohol. The tensile strength was measured indirectly just after treatment and after 3, 6 and 10 days. And released glutaraldehyde from glutaraldehyde- treated fascia was measured after washing for 10 min, 30 min and 60 min. The glutaraldehyde treated group showed the highest tensile strength and the glutaraldehyde and formaldehyde treated groups seemed to have adequate molding effects. Glutaraldehyde was released from treated fascia even in the 60 min washed group. As far as physical properties are concerned, this study suggested that glutaraldehyde-treated temporal muscle fascia may be a tool in otologic reconstructive surgery, and adequate concentration of glutaraldehyde and washing time should be established in order to eliminate possible toxicity.