The present invention relates to an alphabet input system comprising: a plurality of representative keys for inputting matched first letters of the alphabet; and a combination key for generating combination letters of the alphabet that are excluded from the first letters and that are input by a combination with one of the plurality of representative keys, wherein each combination letter is pictographically derived from the shape of the first letter matched respectively to the plurality of representative keys and from a combination symbol of the combination key having a “reverse J” shape. Accordingly, the alphabet can be input more quickly and accurately by combining intuitive and consistent pictographic symbols in a miniaturised input device.