This article examines the legal issues that may arise in a business transfer, the most representative form of business change. Any business change, regardless of its purpose or legal form, presents a variety of labor law questions regarding labor relations. The most basic question is whether the employment will be succeeded. If a transfer of employment is recognized, a number of legal questions arise. In terms of the individual employment relations, a question first arises whether the working conditions provided in the work rules will be succeeded. If the work rules are succeeded, two or more working conditions would exist in one worksite. This circumstance raises a question as to whether it contradicts the equal-treatment principle. If an employer attempts to unify the multiple working conditions, unilateral adverse changes in the work rules would occur. Then, a question arises as to whether the changes would meet the “"reasonableness”" accepted in a society, which the case law requires as a condition to unilateral changes in the work rules. Also, a question may arise as to whether dismissal of employees may be legitimate. In terms of the collective labor relations law, issues such as whether the status of labor unions would maintain after the business change and whether collective agreements will succeed would arise. These questions may arise in every kind of business changes, compelling one to consider every aspect - ‘the alpha and omega’- of the labor law. Unfortunately, however, Korea has no codified rules with regard to these questions, leaving their solutions to interpretation of court decisions by courts and legal theories by scholars. This article has discussed basic labor law issues that might arise from business change.