La
_{1-x}
(Ca, RE)
_x
VO
_3
(0⩽ x ⩽ 1) composition-spread films were fabricated successfully by Combinatorial Pulsed Laser Deposition (CPLD). The structures and thermoelectric (TE) properties of the films were evaluated paralelly by Concurrent X-ray Diffraction (CXRD) and Multi-channel Thermoelectric Measurement systems respectively. The CXRD (200) peaks of the composition-spread films changed linearly, which indicated that the composition-spread films formed solid solution in the whole composition range (0 ⩽ x ⩽ 1). The effects of oxygen content and the substitutions of Ca and rare earth (RE: Ce, Nd, Eu) ions on TE properties of LaVO
_3
were also analysed respectively. There was little change in the Seebeck coefficients of LaVO
_3
films grown at different growth temperatures, while the resistivity decreased with the enhance of the growth temperatures. The largest power factor (0.7 μW/cm K
^2
) of LaVO
_3
film was obtained at 800°C, while the valence of vanadium ion changed from 3+ to 2+ because of the lack of oxygen. With the increase of the content of Ca
^{2+}
ions, the valence of vanadium ion changed from 3+ to 4+, which was responsible for the decrease of TE properties in La1-xCaxVO
_3
system. The substitution of RE (Ce, Nd, Eu) ions for La ions changed not only Seebeck coefficient but also resistivity, but power factor (α) was not increased obviously. In La1-xCexVO
_3
system, La ion took 3+, and Ce ion took 3+ although Ce
^{4+}
was stable in theory, which caused the valence of V ion not changed as expected from 3+ to 2+. The reason may be that the size of Ce
^{3+}
ion is similar to that of La
^{3+}
ion, so Ce takes the valence of 3+ easily in LaVO
_3
.
