${\mathrm{Ta}}_{2}{\mathrm{S}}_{2}\mathrm{C}$ compound undergoes superconducting transitions at ${T}_{\mathit{cl}}=3.60\ifmmode\pm\else\textpm\fi{}0.02\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ and ${T}_{\mathit{cu}}=9.0\ifmmode\pm\else\textpm\fi{}0.2\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. The nature of successive superconducting transitions has been studied from electrical resistivity and linear and nonlinear ac magnetic susceptibilities. The resistivity $\ensuremath{\rho}$ at $H=0$ shows a local maximum near ${T}_{\mathit{cu}}$, a kinklike behavior around ${T}_{\mathit{cl}}$, and reduces to zero at below ${T}_{0}=2.1\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. The $\mathrm{ln}\phantom{\rule{0.2em}{0ex}}T$ dependence of $\ensuremath{\rho}$ is observed at $H=50\phantom{\rule{0.3em}{0ex}}\mathrm{kOe}$ at low temperatures, which is due to a two-dimensional weak-localization effect. Below ${T}_{\mathit{cu}}$, a two-dimensional superconducting phase occurs in each TaC layer. The linear and nonlinear susceptibilities ${\ensuremath{\chi}}_{1}^{\ensuremath{''}}$, ${\ensuremath{\chi}}_{3}^{\ensuremath{'}}$, ${\ensuremath{\chi}}_{5}^{\ensuremath{'}}$, and ${\ensuremath{\chi}}_{7}^{\ensuremath{'}}$ as well as the difference $\ensuremath{\delta}\ensuremath{\chi}$ $(={\ensuremath{\chi}}_{\mathit{FC}}\ensuremath{-}{\ensuremath{\chi}}_{\mathit{ZFC}})$ between the field-cooled (FC) and zero-field-cooled (ZFC) susceptibilities start to appear below $6.0\phantom{\rule{0.3em}{0ex}}\mathrm{K}$, the onset temperature of irreversibility. A drastic growth of the in-plane superconducting coherence length below $6.0\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ gives rise to a three-dimensional superconducting phase below ${T}_{\mathit{cl}}$ through interplanar Josephson couplings between adjacent TaC layers. The oscillatory behavior of ${\ensuremath{\chi}}_{3}^{\ensuremath{''}}$, ${\ensuremath{\chi}}_{5}^{\ensuremath{''}}$, and ${\ensuremath{\chi}}_{7}^{\ensuremath{''}}$ below ${T}_{\mathit{cl}}$ is related to the nonlinear behavior arising from the thermally activated flux flow.