The cancellous bone is a porous piezoelectric material containing the fluid with charged ions. This material is important in calcified biological tissues, such as bone and tooth. The fluid flow containing charged ions as well as piezoelectricity stimulates new formation in bone. We derive the general governing equation for a porous material containing the fluid with charged ions, and solve the analytic solution, which can be used easily. The ultrasound simulates new bone formation. Thus the governing equation for wave propagation is dervied for a porous material containing the fluid with charged ions. The advantage of this study is to bring the analytic solution. Numerically the wave velocity and attenuation are plotted for piezoelectric constants and charge ions. However, these results of charge ions were not measured experimentally. Thus we believe that the NMR may be required to measure the amount of charge ions due to ultrasound in experiments, which will be our future study. Keywords: Ultrasound, Piezoelectricity, Charge ions, Porous material