Abstract: A method of indexing a dictionary and an indexing system thereof comprising the steps of: dividing the fore edge of a dictionary into an upper indexing area and a lower indexing area; diagonally labelling the twenty six English letters in alphabetical order on the upper indexing area of the fore edge according to the pages covered by the same first letter of the entries on a coordinate basis; marking the five English vowels A, E, I, O and U in the lower indexing area on the fore edge of the pages covering each vowel letter being arranged diagonally for corresponding to the relevant locations of the alphabets in the upper indexing area; and providing a plurality of labelling symbols to be respectively marked on both the upper and the lower indexing areas for separately representing the second and the third letters of an entry; so that, by referring to the letters and symbols on the divided fore edge of the dictionary, any entry that is sought can be quickly and accurately located therewith.