A statistical experiment method was employed to investigate the window of the thermal stability of $TiSi_2$films which are popular for Ti-salicide and ohmic layers. The statistical experimental results showed that the first order term of $TiSi_2$thickness and annealing temperature was acceptable as a function of $Delta$resistivity by 95% reliability criteria, and R-sq value implying a fit accuracy of the model also showed a high value of 93.80%. We found that $Delta$resistivity of the $TiSi_2$film annealed at $700^{circ}C$ for 1 hr changed from 3.35 to $0.379mu$$Omega$$cdot$cm with increasing thickness from 185 to $703AA$, and TEX>$Delta$</TEX>resistivity of the $TiSi_2$film with a fixed thickness of 444 $AA$ changed from 0.074 to 17.12 $mu$$Omega$$cdot$cm with increasing temperature increase from 600 to $800^{circ}C$. From these results, we report that the process conditions of$ 692^{circ}C$-1 hr, $715^{circ}C$-1 hr, and 73$0^{circ}C$-1 hr for $TiSi_2$($400 AA$) are stable by the criteria of 1, 2, and 3 $mu$$Omega$$cdot$cm of $Delta$resistivity, respectively.