A mobile terminal and method to write protect a memory card in the mobile terminal. The mobile terminal comprises a body, a battery and a battery cover. The battery cover has a short-circuit connecting member. A memory card socket accommodates a pluggable memory card. A writing control unit has input and output ports, and when the battery cover is jointed with the body, the input and output ports contact the short-circuit connecting member to form a short-circuit connection therebetween; the writing control unit detects whether the battery cover is removed by outputting a test signal from the output port and detecting for the test signal at the input port; if the battery cover is removed, the test signal is not detected at the input port and data is prohibited from being written into the memory card.