Word recognition test (WRT) for the children can be useful for diagnosing the degree of communication disability, prescribing hearing instruments, planning aural rehabilitation and speech therapy, and determination of site of lesions. It is important to use appropriate testing materials for the different langage developmental levels according to the age. As the Korean monosyllabic word lists for the children were not standardized properly, the purpose of this study was to develop the Korean standard monosyllabic word lists for school aged children and preschoolers (KS-MWL-S & KS-MWL-P). Considering the criteria given by the literatures such as phonetic balance and equal range of phonetic composition of speech, words in common usage, and words’ familiarity, etc, first 1,739 & 1,351 monosyllabic words were selected for candidates of KS-MWL-S & P. Those were extracted from the conventional lists, the first and second graded familiar words, the words that were included in the dictionary, children’s books, published articles, and children’s TV program. In order to reflect the actual frequencies of syllable in general colloquialism, initial and final consonants’ and vowels’ frequencies in everyday dialogue were investigated and controlled. The KS-MWL-S & P were developed with selected final 100 monosyllabic words, respectively, followed by examinations of psychometric functions and homogeneity of the stimulus and corrections referred by the experts. The psychometric function tests were performed with the identical method with the KSMWL- A development. The subjects were 30 children (mean age：9.23) for the school aged children’s list and 8 children (mean age： 5.75) for the preschoolers’ list. The mean slopes were 6.49 and 3.07 and the words that were within 1.00 standard deviations of the slope and the level were only included. Picture recognition tests were also performed to 3-4 years old 91 children for verification of the pictures that are drawn by the professional illustrators followed by the corrections. The KS-MWL-S & P 100 words were composed of conventional word lists by Hahm (1962) with 67% (67 words) for the school aged children’s list and 68% (68 words) for the preschoolers’ list, the first and second graded familiarity words with 98% (98 words) for both lists. Also, consonant-vowelconsonant formation was mostly composed with 60% (60 words) for the school aged children’s list and 71% (71 words) for the preschoolers’ list and noun class was 97% (67 words) for the school aged children’s list and 99% (99 words) for the preschoolers’ list, 52% (104 words) and 97.5% (196 words). Four lists were balanced based on equal average difficulty and equal phonetic composition and homogeneity statistically for both word lists. In the KS-MWL-S, the first 10 words on each list were controlled with easy words considering application to the 6-8 years old and the full lists were composed with general school aged children word such as the 9-12 years old. In the KS-MWL-P, the first 10 words on each list were also controlled with easy words considering application to the 3-4 years old and the 20 words on each list were composed with general preschoolers’ application. The last 5 words on each list were added with a little harder words for the usage of multi-handicapped and delayed developed children and adults over 5 years old. However, there were some limitations in developing the KS-MWL-S & P for that graded familiarity was not systematical, that psychometric functions should have been analyzed for all the drafted lists, that the frequency of phonemes should have been based on the age-dependent information, and that the word frequency and lexical effects were not considered based on the neighborhood activation model. Moreover, the verification of this study should be further performed including many hearing impaired children. And analysis of the frequency of the words of these lists and new computerized technology can assist for the utiliza-tion to the clinical and rehabilitative training tool of the KS-MWL-S & P. KEY WORDS：Word recognition test (WRT)·Korean standard monosyllabic word lists for school aged children (KS-MWL-S)· Korean standard monosyllabic word lists for preschoolers (KS-MWL-P)·Phonetic balance·Familiarity· Psychometric function curves·Homogeneity of the stimulus·Rehabilitative training tool.