  We report the magnetization, electrical resistivity, specific heat
measurements and band structure calculations of layered superconductor
SnTaS$_2$. The experiments are performed on single crystals grown by chemical
vapor transport method. The resistivity and magnetic susceptibility indicate
that SnTaS$_2$ is a type-II superconductor with transition temperature $T_c =
3$ K. The upper critical field ($H_{c2}$) shows large anisotropy for magnetic
field parallel to $ab$ plane ($H//ab$) and $c$ axis ($H//c$), and the
temperature dependence of $H_{c2}$ for $H//ab$ shows obvious unconventional
upward feature at low temperature. Band structure of SnTaS$_2$ shows several
band crossings near the Fermi level, which form three nodal lines in the k$_z$
= 0 plane resulting in drumhead-like surface states when spin-orbit coupling is
not considered. These results indicate that SnTaS$_2$ is a superconductor with
possible topological nodal line semimetal character.
