In this paper, we analyzed the effects of the number of TIPS-pentacene droplets and also the substrate temperature on the performance of OTFTs. As the number of the droplets increased, the mobility increased and reached the peak value and then reduced at the all temperatures. The peak mobility was $0.14{pm}0.03cm^2/V{cdot}sec$ at 3 droplets and $41^{circ}C$, $0.19{pm}0.02cm^2/V{cdot}sec$ at 4 droplets and $46^{circ}C$, and $0.35{pm}0.10cm^2/V{cdot}sec$ at 7 droplets and $51^{circ}C$. The reason of existence of peak mobility can be found in matching the evaporation of solvent with the velocity of crystal formation. When two parameters were properly matched, the mobility produced the highest.