This study developed a multi-ions sensing system that includes pH, potassium, sodium, and chloride ion sensors with a wireless home-care system. The pH sensor was based on a tin oxide (SnO )/indium tin oxide (ITO) glass, and the potassium, sodium, and chloride ion sensors were based on the pH sensor with sensing membrane. The tin oxide (SnO) sensing membrane was deposited on indium tin oxide (ITO) substrate using a sputtering system. The sensing membranes of the ion sensors were prepared by mixing poly (vinyl chloride) (PVC), bis (2-ethylhexyl) sebacate (DOS), ionophores, and additives. According to the experimental results, sensitivities of the sensors all were over the value 51 mV/decade. The linear range of pH sensor was between pH2 and pH12, the linear ranges of potassium, sodium, and chloride sensors all were over from 1 mM to 1 M. Therefore, the multi-ions sensing system is suitable for monitoring of blood electrolytes. The correlations of the multi-ion sensors under different test solutions also were discussed. Moreover, this study also investigated sensors module, portable module, Bluetooth module, personal computer (PC) terminal, and portable unit of the wireless home-care system. A graphical measurement interface for data recorded and measurement results displayed was designed by National Instrument Lab-VIEW software. According to the experimental results, the measurement data by the wireless home-care system are near the real values. The wireless home-care system could successfully monitor and transmitted the sensing signals.