Mentalization-based treatment (MBT) is a psychotherapy derived from the psychoanalytic developmental theory and tailored for patients with borderline personality disorder (BPD). In Taiwan, there is still lack of systemic review of the theory of mentalization or MBT. In light of this, we attempt to depict the theoretical basis and research evidence of MBT and explore the techniques in practice. Previous randomized controlled trials have proved that MBT is effective and the effectiveness is sustainable for BPD patients. One feature of MBT is that it can be implemented by generic mental health workers and relatively less additional training is required. Both the treatment guidelines of the UK and the USA declare that psychotherapy is considered the treatment of choice for patients with BPD, and evidence supports that MBT is an effective treatment for them and has the potential to be applied to various fields related to cases with BPD.