Enterprise Resource Planning (ERP) has become an essential information tool for modern enterprises. Enterprises should adjust existing processes to meet the ERP framework or keep them and customize the ERP when implementing it. The most practical way to implement it is partial ERP customization. This study selected the biggest ERP consulting company as the example for the case study, followed by a questionnaire survey to explore the decision factors of the consulting company for ERP customization.The analysis of results of the questionnaire shows consultants consider cost and time while they assess the possibility of ERP customization and they value more the necessity and useful results of it in a long run than rise in benefit in a short run. The situation analysis reveals consultants take a positive attitude to some particular industries like electronic, specific industries for ERP customization; relatively, a negative attitude to some non-representative traditional industries. It also suggests experienced consultants focus more on creating value in a long term considering ERP customization. Therefore, there is significant differentiation among attitudes of consultants from different seniorities for ERP customization.The main contribution of this study is that in the future, consultants may refer to the decision factors for ERP customization in it and design a customization-related check form into which these factors they stress are translated to provide them with a quick reference index for customization assessment. This index may improve the quality of the assessment of consultants on consistency and preciseness.