Titanium salt adsorption behaviors in the citric acid aqueous solution on domestic silk fabric and its effects on flame retardancy were examined. For the evaluation of flame retardancy, the following methods were used: 45$^{circ}$ angel burn test, thermal gravimetric analysis (TGA) and differential thermal analysis (DTA). The results are as follow. 1. The adsorbed amount of titanium salt on silk fabric is varied to some extent with the treating conditions, thus, salt increased with increassing of treating temperature, time and citric acid concentration of solution. 2. Titanium salt are effectual for flame retardancy on silk at smaller add-on as on wool but Zirconium salt are not so effectual as titanium salt. 3. It has been observed that titanium salt lower the onset temperature of phyrolysis and in crease char amount after pyrolysis. 4. The peaks of pyrolysis velocity (dw/dt) obtained from plots of dw/dt vs temperature were some what shifted to higher temperature in contrast with that of untreated silk. 5. All the silk fabrics show an initial endothermic reaction at about 100$^{circ}C$ on account of the evaporation of absorbed water. The second endothermic peaks appear at 310∼315$^{circ}C$ according to the titanium salt add-on amount. 6. It have the tendency to decrease the specific reaction rate constant and activation energy according to the titanium treatment. Its values are decreased with the increase of the titanium salt add-on.