As end-consumers are surrounded by a tremendous number of multi-channel retailers and their products, clothing retailers are exposed to numerous clothing samples with a variety of styles in various price ranges, offered by onshore and offshore manufacturers. Although manufacturers or vendors offer well-salable products, a retail business may not be successful in maximizing profits without a strategic retail buying planning process. The purpose of this study is to develop a retail buying model for clothing retailers. In order to test the variables that comprise the retail buying model, the objectives of the study are to: (a) investigate important assortment decision factors for clothing retail buying; (b) segment clothing retail buyers by their decision factor uses; (c) characterize the segments by buyer (i.e., age, gender, education, experience, employment) and company demographics (i.e., types of products, type of store, size of the firm); (d) examine the relationship between these demographic variables and the factor uses; (e) examine the influence of the factor uses on the success of assortment planning; (f) examine the influence of the success of assortment planning on firm performance; and, (g) examine the influence of extraneous variables (i.e., retail environment) on firm performance. After two pilot tests, adjustments were made to wording in the questionnaire. Data collection, using a pen and paper questionnaire, was conducted using convenience and snowball sampling. Through this method, 425 clothing retail buyers, merchandisers, or store owners, who are involved assortment planning and buying in South Korea, participated in the survey. A variety of statistical analyses was used to test the hypotheses. For testing Hypothesis 1, the mean and standard deviation of the assortment factor items were used to rank important decision factors for assortment planning. To test Hypothesis 2, retail buyers were segmented by their assortment decision factor use through exploratory factor analysis and K-means cluster analysis. For Hypothesis 3, Chi-square was utilized to characterize the segments of buyers and merchandisers from Hypothesis 2, using buyer and company demographics. For Hypothesis 4, Pearson and Spearman Correlations were used to test if correlations exist between buyer and company demographic variables and decision factor use. For Hypotheses 5 to 7, a Structural Equation Model (SEM) was developed to test if causal relationships exist among assortment decision factor use, the success of assortment planning, firm performance, and retail environment. All Hypotheses were fully or partially supported. Based on the results of hypotheses testing, the finalized retail buying model was developed. The finalized retail buying model based on the use of assortment decision factors will benefit retailers by helping retail buyers to analyze available information and identify the need for additional decision factors. Due to the use of convenience and snowball sampling as well as the limited geographic location of the survey, the finding of the current study cannot be generalized to the general population of clothing retail buyers. Future studies using probability sampling methods, utilizing qualitative methods, and/or examining in different countries, are suggested to verify the current findings and confirm the validity of the framework. / Ph. D.