Purpose - In this research, we investigate the relationship between the level of information technology utilization, social capital and knowledge management, organization performance. For information and knowledge management, participants’ certain level of information technology utilization is required and connections among participants are necessary for performing and for synergy effects. Research design, data, and methodology - Reflecting on these, we empirically analyze the effects of participant’s information technology utilization level and social capital on knowledge management and organization achievement for the case of Incheon International Airport. Questionnaire is distributed to the airport employees and collected 221 samples for analyzing. SPSS and AMOS statistic programs are used for analysis. Factor analysis, Credibility adaptability, path analysis, hypotheses are verified. Results - The study research shows as follow. First, the level of IT utilization does affect social capital but does not affect knowledge management. Second, social capital affects both knowledge management and organization achievement. To investigate more about the relationship between the level of IT utilization and knowledge management, we analyzed the control effects of personal characteristics, and findings are, first, employees with longer time service recognize the importance that the level of IT use and knowledge management affect organization achievement more seriously than employees with shorter time service do. Second, employees with shorter time service and younger employees have relatively lesser social capital and participate in knowledge management passively. Third, higher position employees think that the level of IT utilization affects knowledge management while lower position employees do not. Conclusions – The level of IT utilization affects social capital, and social capital affects knowledge management and organization achievement. These results suggest that the level of IT utilization is very important to both organization and each employee. So providing related training and education opportunities or incentives to induce employees to make efforts for higher level of IT utilization and thus to participate in knowledge management more actively is necessary. The level of IT utilization affects social capital which airport employees lack. The one of study results indicates the importance of social capital and for higher competitiveness of the airport social capital should be increased.