This study investigated the use of grammatical morphemes (substantive morphemes and connective endings) of Korean speaking children with and without language impairment (LI). Participants were two children (ages 5;11 and 6;2) with SLI (specific language impairment), two LD (language delay) children (ages 6;3 and 6;5) with 70-84 range on a performance-IQ test, and two children (ages 5;7 and 6;1) with ND (normal development). Spontaneous language samples were elicited by play activities and story generation. A total of 8,059 (M=I,343, ranged 966-1,659) intelligible and nonimitative utterances were analyzed by the KCLA 2.0 (Korean Computerized Language Analysis 2.0) program for substantive morphemes and connective endings. The findings of this study were as follows; (1) The Korean speaking children with LI including SLI demonstrated less uses of grammatical morphemes than ND children. (2) Few differences were found between LI and ND children in the use of the grammatical morpheme types. (3) LI children produced significantly higher percentage of grammatical morpheme errors in spontaneous speech than ND children. (4) Few differences were found between SLI and LD children in degrees of the use and the error of grammatical morphemes.