The purpose of this study is to examine factors that have an influence for deciding forms of shorthands in Korean. In this paper, I will use the word "shorthand forms" means reduced form in several syllables from phrases or sentences and they have no connection with words formations. In Korean Language, the method that is making new words by reducing parts of form is relation to sino-korean words. Recently it has a tendency to increase that reduced form in several syllables from phrases or sentences and no relation language kinds in mass media and SNS. Reduced forms in several syllables from phrases or sentences follow the manner of abbreviations``s formation; acronyms, clipping, blending. Acronyms and clipping manner is systematic, blending manner is not. Blending manner has no rules about reduced parts and remained parts. The most power of influences that formation of shortened form is frequency to view and high recognition. Shorthand form is used like words. So it influenced 2,3 syllables that it is general syllables in Korean words. The selection of syllables composing shorthand is relevant to the maintenance of the main meaning and a possibility of recovering of original form. It is general that shorthand evade homonym but sometimes makes homonym intentionally for increasing frequency to view and publicity.