Objective To evaluate the use of inferior vena cava respiratory variation index (IVC‑RVI) in predicting the volume changes caused by tourniquet placement during knee arthroscopic surgery, so as to facilitate clinical prediction of volume changes caused by tourniquet placement. Methods A total of 85 patients undergoing knee arthroscopic surgery under general anesthesia from October 2018 to July 2019 were enrolled. Tourniquets were used for all the patients. Their IVC‑RVI before tourniquet placement as well as heart rate, mean arterial pressure (MAP) and stroke volume (SV) before and after tourniquet placement were recorded. The gold standard for evaluating the capacity reactivity was stroke volume variability (SVV)≥15%, and all the patients were divided into a capacity reactivity (CR) group and a non‑capacity reactivity (NCR) group. The correlation between IVC‑RVI and SVV was analyzed. The receiver operating characteristic (ROC) curve of IVC‑RVI in predicting CR was plotted to calculate the area under the curve (AUC), Youden index and sensitivity and specificity. Results There was a positive linear correlation between IVC‑RVI and SVV (r=0.655, P<0.05). The AUC of IVC‑RVI in predicting CR was 0.899 (95%CI=0.835‒0.963, P<0.05). The cut‑off value was 17.3%, with a sensitivity of 79.2% and a specificity of 86.5%. Conclusions During knee arthroscopic surgery under general anesthesia, IVC‑RVI can effectively predict the volume changes caused by tourniquet placement, with certain clinical application value.