Taking work groups that apply diverse employment as research subjects, this present study discusses the meaning and the status of faultlines based on employment status, and aims to discover the activating effects of three group contextual factors through interviewing 22 standard and nonstandard workers from 11 diverse-employment work groups according to grounded theory. Results show that the differentiation of human resource policies, employment policies on nonstandard employment (term of employment and temp-to-perm mechanism), and interpersonal relationship climate are three core group contextual factors that activate employment-status-based group faultlines. To be specific, differentiation of human resource policies and term of employment on nonstandard workers can directly activate dormant employment-status-based group faultlines. This effect is moderated by temp-to-perm mechanism and interpersonal relationship climate. Moreover, the direct and indirect activating effects above are mediated by the salience of employment status as a social category.