Objective To observe the value of apparent diffusion coefficient(ADC)for evaluating short-term efficacy of TACE for treating colorectal cancer liver metastases(CRLM).Methods Data of 60 liver metastases in 28 CRLM patients who underwent TACE were retrospectively analyzed.Based on MRI after the first TACE,according to the response evaluation criteria of solid tumors,the liver metastases were divided into response group(n=38)and non-response group(n=22).ADC parameters obtained with diffusion weighted imaging(DWI)before and after TACE,including ADC before TACE(ADCpre),after the first TACE(ADCpost1)and after the second TACE(ADCpost2)were compared between groups,while ADC change value(ΔADC)and the percentage of ΔADC were calculated.The maximum diameter of the target foci were measured,and the correlation between ΔADCpost1 and the change of the maximum diameter of target foci were analyzed.Receiver operating characteristic curve was drawn,the area under the curve(AUC)was calculated to observe the efficacy of ΔADCpost1 for evaluating short-term efficacy of TACE for CRLM.Results No significant difference of ADCpre was found between groups(P=0.484).After the first TACE,ADCpost1,ΔADCpost1 and percentage of ΔADCpost1 in response group were all higher than those in non-response group(all P＜0.05).After the second TACE,no significant difference of ADCpost2,ΔADCpost2 nor percentage of ΔADCpost2 was found between groups(all P＞0.05).The maximum diameter change of the target foci after the first TACE was(-0.48±0.93)cm,which was negatively correlated with ΔADCpost1(rs=-0.347,P=0.007).AUC of ΔADCpost1 for evaluating short-term efficacy of TACE for CRLM was 0.717.Conclusion ADC had good efficacy for evaluating short-term efficacy of TACE for treating CRLM.