A series of perovskite-type compounds La1-aCaaCr0.2Ti0.8O3 -delta (a = 0.6 - 1.0) was synthesized by a ceramic technique in air (final heating 1350 degreesC. For 0.4 < a < 0.6 the crystal structures of the compounds cooled in air were characterised at room temperature as rhombohedral in space group R-3c, and for a > 0.6 as orthorhombic in space group Pbnm. The lattice constants for a > 0.8 decrease noticeably with increasing Ca content and for a < 0. 8 they remain nearly constant. All compositions were stable in air and in Ar/l Pa O-2 at 20-1400 degreesC, and in 5% H-2/Ar (pH(2)O/pH(2) = 0.01) at 850-1000 degreesC. Oxygen stoichiometries and electrical conductivities of the solid solutions with a = 0.6 to 1.0 were investigated. Increasing Ca-contents decrease the stability of the oxides in respect to the thermal dissociation with oxygen release. At 900 degreesC within the oxygen partial pressure region 1 X 10(-15) to 0.21 X 10(5) Pa the compounds with a>0.8 are p-type and with a<0.8 n-type semiconductors. La0.2Ca0.8Cr0.2Ti0.8O3 - delta changes its conductivity type from n-type at PO2 < 10(-10) Pa to p-type in more oxidizing atmosphere. For the compound with a = 0.6 in 5% H-2/Ar flow at 1000 degreesC, a maximum conductivity of about 50 S/cm has been observed. In air the composition with a = 0.95 has the highest conductivity of about 1 S/cm. In an oxidizing environment the maximal conductivities correspond to the ratio [Cr3+]/[Cr4+] = 1 (corresponding to an oxygen stoichiometry near 3.0), and in reducing environment to the ratio [Ti3+]/[Ti4+] = 1 (corresponding to an oxygen stoichiometry near 2.95).