We present twelve new transit light curves of the hot-Jupiter TrES-3b observed during 2012 - 2018 to probe the transit timing variation ( TTV ) . By combining the mid-transit times determined from these twelve transit data with those re-estimated through uniform procedure from seventy one transit data available in the literature , we derive new linear ephemeris and obtain the timing residuals that suggest the possibility of TTV in TrES-3 system . However , the frequency analysis shows that the possible TTV is unlikely to be periodic , indicating the absence of an additional body in this system . To explore the other possible origins of TTV , the orbital decay and apsidal precession ephemeris models are fitted to the transit time data . We find decay rate of TrES-3b to be \dot { P _ { q } } = -4.1 \pm 3.1 ms { yr } ^ { -1 } and the corresponding estimated modified tidal quality factor of { Q } ^ { { } ^ { \prime } } _ { \ast } \sim 1.11 \times { 10 } ^ { 5 } is consistent with the theoretically predicted values for the stars hosting the hot-Jupiters . The shift in the transit arrival time of TrES-3b after eleven years is expected to be { T } _ { shift } \sim 69.55 s , which is consistent with the RMS of the timing residuals . Besides , we find that the apsidal precession ephemeris model is statistically less probable than the other considered ephemeris models . It is also discussed that despite the linear ephemeris model appears to be the most plausible model to represent the transit time data , the possibility of the orbital decay can not be completely ruled out in TrES-3 system . In order to confirm this , further high-precision and high-cadence follow-up observation of transits of TrES-3b would be important .