Neurons in the primary visual cortex (V1) selectively respond to a bar projected onto their receptive fields and corresponded to their preferred orientation (orientation selectivity). Recent studies have revealed that the cortical microcircuit in the superficial layers (2/3) of V1 consisted of excitatory neurons and three major subtypes of inhibitory interneuron: parvalbumin (PV), somatostatin (SOM), and vasoactive intestinal polypeptide (VIP) neurons. These neuronal populations interacted with each other to form functional microcircuits for processing visual feature such as orientation selectivity. However, the structural organization of local interactions and horizontal connections between neighboring orientation-selective microcircuits sharing the common receptive field in V1 remains poorly understood. In this study, to understand the fundamental microcircuit structure underlying orientation selectivity in V1 and investigate the roles of specific inhibitory interneuron subtypes for mediating the horizontal connections within the receptive field, we developed a computational microcircuit model of the orientation selectivity with biologically plausible layers 2/3 of V1 that combined excitatory neurons and three inhibitory interneuron subtypes. In this model, two functional microcircuits with orthogonal orientation selectivity interacted via horizontal connections from excitatory neurons in one unit to PV or SOM inhibitory interneurons in the other. Our model simulations with various visual stimuli mimicking the specific oriented bars implied that the horizontal connections from excitatory neurons in one microcircuit to SOM interneurons in another may contribute to the generation of the neuronal responses in V1 to the specific orientation. These results suggest that SOM inhibitory interneurons play a key role in the local integration of orientation-specific information and provide new insights into the circuit mechanisms underlying human visual perception.