HESS J1912+101 is a shell-like TeV source that has no clear counterpart in multiwavelength. Using CO and H I data, we reveal that V-LSR similar to + 60 km s(-1) molecular clouds (MCs), together with shocked molecular gas and high-velocity neutral atomic shells, are concentrated toward HESS J1912+101. The prominent wing profiles up to V-LSR similar to + 80 km s(-1) seen in (CO)-C-12 (J = 1-0 and J = 3-2) data, as well as the high-velocity expanding H I shells up to V-LSR similar to + 100 km s(-1), exhibit striking redshifted-broadening relative to the quiescent gas. These features provide compelling evidences for large-scale perturbation in the region. We argue that the shocked MCs and the high-velocity H I shells may originate from an old supernova remnant (SNR). The distance to the SNR is estimated to be similar to 4.1. kpc based on the H I self-absorption method, which leads to a physical radius of 29.0 pc for the similar to(0.7-2.0) x 10(5). years old remnant with an expansion velocity of >= 40 km s(-1). The +60 km s(-1) MCs and the disturbed gas are indeed found to coincide with the bright TeV emission, supporting the physical association between them. Naturally, the shell-like TeV emission comes from the decay of neutral pions produced by interactions between the accelerated hadrons from the SNR and the surrounding high-density molecular gas.