Objective To explore the clinical value and guiding role of Tei index in evaluating right ventricular function of patients with neonatal pneumonia.Methods From January 2020 to December 2021,120 cases of neonatal pneumonia admitted to the Department of Neonatal Pediatric Ward of Zhaoqing First People′s Hospital were selected as the observation group,and they were divided into the common pneumonia group and the severe pneumonia group according to the severity of neonatal pneumonia,with 60 cases in each group.Another 60 neonatal of Neonatology Department(excluding heart and lung diseases)were selected as the control group.The three groups were examined by transthoracic echocardiography,and the right ventricular end-diastolic anteroposterior diameter(RVDd),right atrial diameter(RA),right ventricular anteroposterior diameter(RV),and pulmonary artery systolic pressure(PASP)were measured.The right ventricular Tei index was measured and calculated by tissue Doppler technology.Plasma N-terminal probrain natriuretic peptide(NT-proBNP)was measured simultaneously.The levels of RVDd,RA,RV,PASP and NTproBNP in the three groups were compared.Results Upon 24 h of admission,the levels of NT-proBNP,Tei index,PASP values in the common pneumonia group and the severe pneumonia group were higher than those in the control group,the differences were statistically significant(P＜0.05).The levels of NT-proBNP,Tei index and PASP values in the severe pneumonia group were higher than those in the common pneumonia group,the differences were statistically significant(P＜0.05).The levels of RV and RA values in the severe pneumonia group were higher than those in the control group,the level of RVDd value in the severe pneumonia group was lower than that in the control group,the differences was statistically significant(P＜0.05).But there were no significant differences with the common pneumonia group(P＞0.05).After one week of systematic treatment,the levels of NT-proBNP,Tei index and PASP values in the common pneumonia group and the severe pneumonia group were lower than those upon admission,and the levels of NT-proBNP,Tei index and PASP values in the severe pneumonia group were higher than those in the common pneumonia group,the differences were statistically significant(P＜0.05).There were no significant differences in the RV,RA and RVDd between the two groups(P＞0.05).Tei index and NT proBNP concentration of patients in the observation group was significant positive correlation(r=0.45,P＜0.05).Conclusion Tei index of neonatal pneumonia patients is abnormally high,and Tei index and NT-proBNP have a good correlation.The combination of the two indexes can provide relevant disciplinary basis for the evaluation,diagnosis,treatment and efficacy evaluation of clinical neonatal pneumonia.