Objective To study the effect of Levofloxacin combined with Tanreqing injection on pneumonia severity index (PSI) and CURB-65 scores in patients with community acquired pneumonia (CAP). Methods 198 patients with CAP who received treatment in our hospital from March 2015 to March 2017 were randomly divided into two groups. The combined group (100 cases) was treated with Levofloxacin combined with Tanreqing injection, while the control group (98 cases) was given anti-inflammatory treatment with Levofloxacin injection . The evaluation results of severity indexes (PSI and CURB-65 scores) and the differences of serum C reactive protein (CRP) and serum procalcitonin (PCT) between the two groups were compared before and after treatment. Results After treatment, the scores of PSI and CURB-65, and levels of CRP and PCT in the two groups were decreased, and all these indexes in the combination group were significantly lower than those in the control group (P<0.05). Conclusion Levofloxacin combined with Tanreqing injection which is beneficial for regulating the levels of CRP and PCT and promoting the prognosis of disease, can obviously improve the severity of CAP patients.