The synthesis of near-zero-expansion ceramic from Na1-xNbxZr2-x(PO4)3 was investigated. The replacement of Zr4+ and Na+ by Nb5+ decreased the thermal expansion of the c-axis. The thermal expansion of the a-axis was negative. Consequently the average thermal expansion exhibited zero expansion at x÷0.75. Thermal expansion coefficients of Na0.25Nb0.75Zr1.25(PO4)3 are αa=-3.4×10-6/°C, αc=+6.0×10-6/°C, and αavg=-0.3×10-6/°C. Thermal expansion coefficients of Nb Zr(PO4)3 which does not contain Na+ ion are αa=-3.4×10-6/°C, αc=+1.2×10-6/°C, αavg=-1.9×10-6/°C with less thermal expansion anisotropy. The dense ceramics were fabricated by sintering at 1200°-1400°C for 10-60min with MgO as sintering aids. The linear thermal expansion coefficient of the sintered ceramics was near zero.