Objective To evaluate the value of left ventricular myocardial work parameters in evaluating left ventricular function in patients with complete left bundle branch block (CLBBB). Methods 56 patients with CLBBB were selected. According to the decrease of ejection fraction, the patients were divided into two groups: normal ejection fraction group (n=30) and low ejection fraction group (n=26)， while 40 healthy adult volunteers were recruited as control group. The parameters of routine echocardiography, longitudinal peak strain dispersion (PSD), global longitudinal strain (GLS) and left ventricular myocardial work (LVMW) were compared in each group. ，including global work efficiency (GWE), global work index (GWI), global useful work (GCW) and global useless work (GWW). Results There were significant differences in PSD, GLS, GWE, GWI and GWW between EFpreserved group, EFlow group and control group(P＜0.05). There were significant differences in PSD, GLS, GWE, GWI and GWW between EFpreserved group and EFlow group(P＜0.05). There was no significant difference in GCW between EFpreserved group and control group(P＞0.05). There was significant difference in GCW between EFlow group and EFpreserved group and control group (P<0.05). PSD and GLS were negatively correlated with EF, E, e,septal, e,lateral（P＜0.01）. PSD was positively correlated with EDV and ESV(P < 0.05). GLS was positively correlated with EDV、ESV(P＜0.01) and A（P<0.05）.GWE, GWI and GCW were positively correlated with EF, E, e,septal, e,lateral. GWE was negatively correlated with EDV、ESV（P＜0.01）,and A (P=0.02). GWI and GCW were negatively correlated with EDV and ESV（P＜0.01）. GWW was negatively correlated with EF, E, A, e,septal, e,lateral (P＜0.01), but positively correlated with EDV and ESV(P＜0.01). Conclusion LVMW parameters have certain potential clinical value in quantitative evaluation of left ventricular function in patients with CLBBB.