We propose to clarify the magnetic properties of (Nd1-xCax)2Ru2O7 by using muSR. Previous result of ZF-muSR for x = 0 and 0.15 showed that there is a magnetic ordered state below TN indicated by the decreasing of initial asymmetry. The lost initial asymmetry partially recovers at the lower temperature, T4f, where the anomaly in magnetic susceptibility is observed, and gradually decreases again with decreasing temperature. The origin of the anomaly at T4f is still unclear from only ZF measurements. The aim of this study are to investigate the origin of the strange magnetic properties at low temperatures and the ground states by using LF-muSR to reveal the spin dynamics at the muon site and to study the hole concentration dependence of TN, T4f, magnetic properties and ground state for x =0, 0.15, 0.3 and 0.4 by using ZF and LF-muSR. We request 6 days beam time in total for this experiment.