Abstract: Objective To investigate the triglyceride (TG)-lowering effects of PCSK9 inhibitor in patients with in different baseline triglyceride levels. Methods Between February, 2019 and March, 2020, a total of 59 patients were treated with PCSK9 inhibitor (Evolocumab) in 5 hospitals, including Nanfang Hospital, Guangdong Provincial People’s Hospital, First Affiliated Hospital of Sun Yat-sen University, Foshan Nanhai District People’s Hospital and Yulin First People’s Hospital. According to baseline triglyceride levels, the patients were divided into normal TG group (<1.70 mmol/L, n=24), mild hypertriglyceridemia group (1.70-2.29 mmol/L, n=11), moderate hypertriglyceridemia group (2.30-5.63 mmol/L, n=13), and severe hypertriglyceridemia group (≥5.64 mmol/L, n=11), and the changes in TG level after the treatment were compared among the 4 groups. Results In the groups with normal and mildly elevated baseline TG level, the patients did not show significant changes in TG levels after the treatment. In patients with moderately and severely elevated baseline TG levels, treatment with PCSK9 inhibitor significantly reduced their TG levels (P<0.005). Conclusion PCSK9 inhibitor has a significant TG-lowering effect in patients with moderate to severe hypertriglyceridemia but not in patients with only mildly elevated baseline TG level.