Background The clinical pharmacist has been an important partner in clinical treatment team. In China, there is no systematic review to evaluate the effectiveness of clinical pharmacy services on patients' outcomes such as hospitalization days, readmission rate and mortality. Aim of the review To investigate the impact of clinical pharmacist services on patients' length of hospitalization, readmission and mortality in China. Methods A literature search was performed in PubMed, EMBASE, Cochrane Library, clinicaltrials.gov, and a Chinese database (up to January 2019). Randomized control trials or pre- to post-intervention comparison studies were included to investigate the impact of clinical pharmacist-led interventions on the length of stay, readmission rate and mortality of inpatients. Basic information, intervention and therapeutic area were extracted. Results After screening all articles from the mentioned databases, 14 studies were included for meta- analysis and subgroup analysis. Most studies focused on cardiology and respiratory diseases. Results show that clinical pharmacist services can reduce the length of stay of inpatients (MD: - 3.00, 95% CI - 4.72 to - 1.29, P < 0.01) and the readmission rate (RR 0.44, 95% CI 0.35-0.56, P < 0.01) as well as the mortality of patients during hospitalization (RR 0.57, 95% CI 0.35-0.92, P = 0.02). Conclusions Clinical pharmacist-led interventions could significantly reduce Chinese patients' length of hospitalization and readmission rate. More studies are needed to confirm the relationship between the clinical pharmacist-led interventions and patients' mortality.