A new series of 8-(p-substituted-phenyl/benzyl)xanthines has been synthesized and evaluated in vitro for adenosinereceptorbinding affinity and in vivo for bronchospasmolytic effects. It was observed that the nature of substituent at para-position of 8-phenyl/benzyl group on the xanthine scaffold remarkably affects the binding affinity and selectivity of xanthine derivatives for various adenosine receptor