A method for detecting a touch trace is provided. A look up table, including a plurality of position coordinates and calibrating rules f corresponding to each of the plurality of position coordinates, is built. A touch trace including at least one touch point is received, wherein if an actual contact area Ai of the at least one touch point is a basic contact area A0, an actual signal value Vi of the at least one touch point is V0i. Each of the calibrating rules f is to convert the value V0i to a standard signal value Vs. Position coordinates of the at least one touch point are calculated, the actual signal value Vi under the actual contact area Ai is obtained; and the calibrating rule f corresponded is queried. The actual signal value Vi is calibrated to the calibrated signal value V′i.