A method for selecting characters, comprising: sensing a user approaching action or a user touching action on a first key, said first key having a first character, which belongs to a first category, and a second character, which belongs to a second category, marked thereon; displaying said first character and said second character on a display unit in response to said user approaching action or said user touching action, wherein the first character is highlighted as preselected, and the second character is not highlighted; and characterized in that the method comprises: sensing a user's finger shifting motion on said first key after said user approaching action or said user touching action on said first key; selecting and entering the second character in response to said user's finger shifting motion if the user's finger shifting motion is along a direction corresponding to the second character; determining a third character, in response to another user approaching action or user touching action on a second key, as preselected according to a predictive text input method if the second character is entered through the first key, wherein said second character of the first key and said third character of said second key belong to the second category, which is different from the first category, and the determined third character is displayed as preselected and thereafter is selected and entered via a further user approaching action or user touching action. sensing a user approaching action or a user touching action on a first key, said first key having a first character, which belongs to a first category, and a second character, which belongs to a second category, marked thereon; displaying said first character and said second character on a display unit in response to said user approaching action or said user touching action, wherein the first character is highlighted as preselected, and the second character is not highlighted; and characterized in that the method comprises: sensing a user's finger shifting motion on said first key after said user approaching action or said user touching action on said first key; selecting and entering the second character in response to said user's finger shifting motion if the user's finger shifting motion is along a direction corresponding to the second character; determining a third character, in response to another user approaching action or user touching action on a second key, as preselected according to a predictive text input method if the second character is entered through the first key, wherein said second character of the first key and said third character of said second key belong to the second category, which is different from the first category, and the determined third character is displayed as preselected and thereafter is selected and entered via a further user approaching action or user touching action. sensing a user's finger shifting motion on said first key after said user approaching action or said user touching action on said first key; selecting and entering the second character in response to said user's finger shifting motion if the user's finger shifting motion is along a direction corresponding to the second character; determining a third character, in response to another user approaching action or user touching action on a second key, as preselected according to a predictive text input method if the second character is entered through the first key, wherein said second character of the first key and said third character of said second key belong to the second category, which is different from the first category, and the determined third character is displayed as preselected and thereafter is selected and entered via a further user approaching action or user touching action.