This paper reports the progress of one effort to validate an instrument that can be used to measure children`s achievement motivation. The 「Nalongyees」 is developed on the basis of the 「Gumgookies」 by Adkins & Ballif (1970). Through two preliminary studies, 75 items on the Gumgookies were reduced to 60 items idenfied as acceptable. The purpose of the main study was to validate 60 items through two examination at the early stage of the first term & the later stage of the second term. The Subjects of the first term were 111(57 boys, 54 girls) & those of the second term were 114(56 boys, 58 girls) five to six years old children in Pusan & Kimhae City. The major findings were as follows: 1. From the result of item analysis into two different data 12 items were excepted and 48 items identified as acceptable were re-analyzed item easiness, item discriminace & monogeneity of item content. 2. 48 items were arranged 8 areas with a range of 3-13 sub-items on the basis of theonetical relativeness & the results of factor analysis on the preliminary studies. The correlation coefficients between 8 areas and their sub-items were .20-.70 at the first term examination and .07-.75 at the second term examination. The degree of redundancy among 8 areas were also acceptable. 4 factors were extracted from factor analysis into the first term data with 2.70-1.01 eigen value, .27-.73 communality, and 71.6% of the total common factor variance. The results of factor analysis into the second term data were nearly same as those of the first term data. Factors extracted from the first & second term data were "internal standard of excellence" or "physical superiority", "active problem solving", "interests in learning & kindergarthen", "self-confidence". 3. The Cronbach as of the 48 items were. .75, .78 & split-half reliabilities were .65. .63 at the first & second term examination. 4. Preschool children`s achievement motivation differed significantly according to their family`s socio-economic status, mother`s education level at the first term, but not at the scond term. The correlation coefficient between 「Nalongyees」 score (48 items) and teachers` rating scores of children` s achievement motivation was very low.