Ceramics with the formula Ca1-xSrxZr4(PO4)6 (x=0.4, 0.45, 0.5, 0.55) have been synthesized by coprecipitation method, an. their structures, phase transitions, thermal expansion properties have been studied by differential sanning calorimetry, scanning electron microscope, X-ray diffraction and dilatometer. The results show that Ca1-xSrxZr4(PO4)6 ceramics sintered at 1400°C had good sintering condition. Unit cell volume basically had no change with substitution of Ca by Sr. The coprecipitation method saved energy and time. It was introduced to increase the relative density of Ca0.5Sr0.5Zr4(PO4)6 ceramic. The coefficient of thermal expansion was about 1.447×10-6/°C.