<Introduction>It is difficult to identify the region of tumor cells pre or intra-operatively in renal cell carcinomas (RCCs) invading IVC (inferior Vena Cava). Then. it is not desirable to open the IVC wall, because the tumor disseminations will occur. Indeed, pulmonary metastasis and recurrences at IVC walls sometimes occur, so we have decided on our policy to have to resect the tumor with IVC by non touch method and reconstruct IVC using artificial graft for expecting the better late result of the resection RCCs invading IVC. <Methods> From 1998 to 2005, we have en bloc resected RCCs invading IVC and reconstructed IVC using artificial grafts in 6 cases for eight years. Support circulations were required in 4 cases, two cardiopulmonary bypasses and two veno-venous bypasses. Five cases were reconstructed IVC using ePTFE grafts, and one case underwent wedge resection and direct suture of IVC. <Results> All cases were cancer free at IVC margin, but three cases are positive at the cephalous of tumor thrombus. There was no early death but one late death at postoperative 13 months suddenly. Five (included one case with bone metastasis) of 6 cases are survived with patent IVC grafts for 38±30months. <Conclusion> The non touch resection of RCCs invading IVC and reconstruction. may improve the late results.