Telescope Array (TA) is measuring ultra-high energy cosmic rays in the Northern hemisphere since 2008. Using hybrid detectors namely surface detector array (SD) and fluorescence telescopes (FD), TA can measure the lateral and longitudinal developments of extensive air showers, respectively, in detail. Recent analysis of SD data reveals the excess of muons at large distance from the shower core with respect to the MC predictions. Deep penetrating showers observed by FD were used to determine the p-air inelastic cross section. These measurements are useful to study the hadronic interaction beyond the energy of current accelerator reach. In this talk, we will review the TA results relevant to study the high-energy hadronic interaction.