Dielectricand pyroelectric properties of {{{{ { { {Ba }_{0.67 }Sr }_{0.33 } }`TiO_{3 } ^{ } }} (BST) thin plates and films were investigated. For BST thin plates maximum dielectric constant and pyrolelectric coefficient were observed at around 24$^{circ}C$ and pyroelectric characteristics were improved as applied bias field was increased. When the electric field of 4kV/cm was applied to the thin plates sintered at 140$0^{circ}C$ the pyroelectric coefficients over 4$ imes$10-7C/{{{{ { cm}^{2 }K }} were obtained in the range of 0-4$0^{circ}C$ BST thin films deposited using rf magnetron sputtering showed [001] preferred orientation at substrate temperatures above 50$0^{circ}C$ On the contrary to the thin plates the dielectric constants of the thin films gradually increased above 15$^{circ}C$ and decreased as applied bias field in-creased. The pyroelectric coefficients of thin films were lower than 1/10 those of thin plates.