Isothiazolone exhibit a broad-spectral antiseptic actions. The formalin fixed cadavers preserved in 0.1％ isothiazolone aqueous solution for 3 years, revealed that the solution still kept clear, and the colour of the cadavers was well retained, and the gross structure of the cadavers was in good condition. Bacteriostatic test indicated that 0.05-0.1％ isothiazolone solution was highly effective in inhibiting common septic bacteria and fungi, and was reliably effective in inhibiting the aspergillus flavus taken from the surface of the midewy cadavers. The chemical property of the isothiazolone solution was stable, and its T_(1/2) was 93.28 months, and the bacteriostatic effect might keep for 7 years. The solution was colourless, odorless and nonirritant. Toxicity test revealed its LD_(50) was 175mg/kg, and the Ames' mutation test showed a negative result, and the teratologic study indicated that it did not induce any skeletal malformations in neonatal rats. This study suggest that 0.1％ isothiazolone may be used as a preservative to substitute for formaldehyde.