Abstract: The 6th World Symposium on Pulmonary Hypertension was held in Nice between February 28 and March 1, 2018. The major progress in chronic thromboembolic pulmonary hypertension (CTEPH) in the past 5 years was reviewed by the experts of Task Force 11. The definition, classification, pathologic mechanisms, epidemiology, diagnosis, and treatment were updated based on available evidence. Chronic thromboembolic disease (CTED) was defined and the difference between CTED and CTEPH was summarized. All CTEPH patients should be evaluated by a multidisciplinary team. Balloon pulmonary angioplasty (BPA), with improved efficacy and safety, plays an important role in CTEPH therapy. An ongoing study investigates patients with CTEPH who are not eligible for pulmonary endarterectomy and are randomized into medicine therapy or balloon pulmonary angioplasty (BPA), and compares the effects of the two therapies. The combination therapy for CTEPH needs the evidence of a long-term follow-up.