  In this paper, we investigate the topological properties of ZrRuP and
ScPd$_{3}$ using the first-principles calculations. We calculate the electronic
structure, surface states, and Z$_{2}$ topological invariant. The band
structure of ZrRuP without the spin-orbit coupling (SOC) exhibits a nodal line
located at $\Gamma$-K-M high symmetry line in the Brillouin zone(BZ). The nodal
line is protected by the mirror symmetry corresponding to the plane $k_{z}=0$.
The geometry of Fermi surface is a connected torus centered at K point with
open orbits at the boundary of BZ, when the Fermi level is shifted up 0.25 eV.
The inclusion of SOC leads to the gap opening in the band structure which
corresponds adiabatically to transition from nodal line semimetal to
topological insulator. The corresponding surface states were obtained from thin
film calculations, and the result shows surface states emerging along the gap
region. We also identify the ScPd$_{3}$ compound as a Dirac nodal line
semimetal. This structure has nontrivial surface states and the corresponding
Z$_{2}$ topological invariant is (1;000). Both the ScPd$_{3}$ and ZrRuP have
the Fermi surfaces of the bands which make nodal lines with open orbits.
