We deposited amorphous Ba0.7Sr0.3TiO3 (BST) on silicon and plastic substrate under 110 degrees C by pulsed laser deposition (PLD) and use it as the dielectric of the organic transistor. Depends on the thickness of BST layer, the highest mobility of the devices can achieve 1.24 cm(2) V (1) s (1) and 1.01 cm(2) V (1) s (1) on the silicon and polyethylene naphthalate (PEN) substrate, respectively. We also studied the upward and downward bending tests on the transistors and the dielectric thin films. We found that the BST dielectric pentacene transistor can maintain the mobility at 0.5 cm(2) V (1) s (1) or higher while the bending radius is around 3 mm in both upward and downward bending. Our finding demonstrates the potential application of PLD growth high-k dielectric in the large area organic electronics devices. ; Department of Applied Physics ; Department of Mechanical Engineering