Sisterhood Ties, is POSCO's unique regional social contribution program which have been running since1991. The ground rule is one local organization for one department; it supports volunteering activities including medical care, disinfection, and facility repairs, and services. Sisterhood Ties activities promote the good relationship with local communities and work as a communication channel local residents.

• Sisterhood Ties : With 224 towns, villages, schools and organizations
• Pohang: 118 sites, Gwangyang: 106 sites