A series of compositions with general stoichiometry Ca<SUB>1−x</SUB>Zr<SUB>1−x</SUB>Nd<SUB>2x</SUB>Ti<SUB>2</SUB>O<SUB>7</SUB> has been prepared by high-temperature solid-state reaction of component oxides and characterized by powder X-ray diffraction and electron probe for microanalyses (EPMA). The phase fields in CaZrTi<SUB>2</SUB>O<SUB>7</SUB>–Nd<SUB>2</SUB>Ti<SUB>2</SUB>O<SUB>7</SUB> system and distribution of ions in different phases have been determined. Four different phase fields, namely monoclinic zirconolite, cubic perovskite, cubic pyrochlore, and monoclinic Nd<SUB>2</SUB>Ti<SUB>2</SUB>O<SUB>7</SUB> structure types are observed in this system. The 4M-polytype of zirconolite structure is stabilized by substitution of Nd<SUP>3+</SUP> ion. The addition of Nd<SUP>3+</SUP> ions form a cubic perovskite structure-type phase and thus observed in all the compositions with 0.05 ≤ x ≤ 0.80. Cubic pyrochlore structure-type phase is observed as a coexisting phase in the nominal composition with 0.20 ≤ x ≤ 0.90. Only a subtle amounts of Ca<SUP>2+</SUP> and Zr<SUP>4+</SUP> are incorporated into the perovskite-type Nd<SUB>2</SUB>Ti<SUB>2</SUB>O<SUB>7</SUB> structure. EPMA analyses on different coexisting phases revealed that the pyrochlore and perovskite phases have Nd<SUP>3+</SUP>-rich compositions
