1. A method of searching note items, wherein the method includes the following steps: when marking a note item, detecting a gesture input from a touchscreen or choosing a gesture which has been input, and saving the gesture and the corresponding relation between the gesture and the note item into a memory; when a note item needs to be searched, detecting a gesture input from the touchscreen, and according to the input gesture, searching a matching gesture from the gestures saved in said memory, if the matching gesture is found, then displaying each note item corresponding to the matching gesture according to said corresponding relation, wherein said gesture contains the following information: pattern, handwritten speed of strokes making up the pattern, writing area and pressure of strokes making up the pattern, order and track of strokes making up the pattern; and wherein in said step of searching a matching gesture, whether two gestures are matched is determined by the following way: if the similarity of the patterns of two gestures exceeds a predetermined threshold, and the similarity of the handwritten speed of the strokes of the patterns of two gestures exceeds a predetermined threshold, and the similarity of the writing area and the pressure of the strokes of the patterns of two gestures exceeds a predetermined threshold, and the similarity of the order and the track of the strokes of the patterns of two gestures exceeds a predetermined threshold, conforming with the above detection, then determines that the two gestures are matched.