This report was investigate the biological characteristic of $delta$-endotoxin of product by TH109 strain, one strain TH109 which has toxicity on Cockroach is isolate and identification. Generally the $delta$-endotoxin of product by 3. thuringiensis strain was easily soluble in acid, alkaline and organic solvents but $delta$-endotoxin of product by TH109 strain are insoluble in HCI, NaOH Thiol- reagent(25mM Dithiotheritol, 25mM Dithioeryritol, 25mM Nathioglycolate, 0.2M ESCN, 2% v/v $eta$-mecaptethanol), organic solvents( acetone, $CCI_{4}$, ether, dioxin MeOH chloroforrh xylene ), Protease. Through this study of $delta$-endotoxin produced by TH109 strain is insoluble in acid, alkaline, organic solvents and pretense etc. In the point of view, it is greater possibility that $delta$-endotoxin will be transform into toxin by the reducible materials instead of the reaction of protease in the intestine.