This study investigates how different types of inhibitory interneurons contribute to the synchronization of precise spike times across multiple neurons, which is crucial for sensory information processing. By analyzing single-unit recordings from the barrel cortex in vivo and using optogenetics, this study examined the roles of parvalbumin (PV) and somatostatin (SST) interneurons. They found that PV interneurons promote spike time synchronization at low firing rates (<12 Hz), while SST interneurons do so at high firing rates (>12 Hz). A computational model revealed that these effects are due to PV and SST interneurons contributing preferentially to feedforward and feedback inhibition, respectively. This study highlights the frequency-selective roles of distinct interneuron subtypes in synchronizing neuronal activity, which has critical implication in unraveling neural computational principles.