Metamaterials are artificial materials engineered to have exotic properties that may not be found in nature, and it provides a novel tool to significantly enhance the sensitivity of sensors, and open new degrees of freedom in sensing design aspect. In this paper, a metamaterial sensor based on microstrip-line-excited SRR is developed, and its properties are analyzed in theory and simulated by full wave simulations. The results show good agreement with the theory. On this basis, single-channel sensor is extended to two channels and even four channels sensor. By observing and comparing the transmission profile by putting different sample on every channel, we found that the multi-channel sensor can work independently and posses good selectivity. Furthermore, the sensitivity of sensor will be greatly enhanced with the increase of SRR thicknesses. This work would pave a new way to design sensor with higher performance.