Whispering-gallery-mode (WGM) resonance enhanced random laser action has been proposed and demonstrated. To illustrate the working principle, lasing characteristics of ZnO nanorods decorated with SiO2 nanospheres have been investigated. It is found that with the assistance of SiO2 nanospheres, the emission spectrum exhibits a very narrow background signal with few sharp lasing peaks and a very small full width at half maximum of less than 0.3 nm. The differential quantum efficiency (ηd) of random laser action can be greatly enhanced by up to 735 %. The decorated nanospheres not only enable to generate WGM resonance and enhance the emission intensity, but also can serve as scattering centers. Cathodoluminescence mapping images of nanorods decorated with nanospheres and theoretical calculation based on the spherical cavity were utilized to confirm our proposed mechanism. The unique lasing behavior shown here may open up a new approach for the creation of highly efficient optoelectronic devices.