Background: A few reports have shown no difference between the efficacy of infusional FU and that of oral FU (Capecitabine/S-1) for colorectal cancer, and some studies have reported the non-inferiority between infusional FU/Oxaliplatin (OX) and oral FU/OX for metastatic colorectal cancer (mCRC). We performed a sub-group comparison between infusional FU/OX (mFOLFOX6 + BV: iFU) and oral FU/OX (CapeOX/SOX + BV: oFU) from the HGCSG0802 observational cohort study with investigated Japanese patients (pts) treated with first line BV for mCRC. Methods: The objective of HGCSG0802 was to evaluate progression-free survival (PFS), overall survival (OS), time to treatment-failure (TTF), response rate (RR), safety and so on. The key eligibility criteria of HGCSG0802 were with evaluable lesions, older than 20 years, ECOG PS 0-2, and this analysis used the cohort treated with OX-based regimens.In this analysis, pts characteristics, RR and safety were compared using Fisher’s exact test. PFS and TTF were compared using log-rank test. Results: Of 108 pts (the full analysis set), 95 pts were evaluable for treated with OX-based regimens. Forty-eight pts (50.5%) were treated with iFU and 47 pts (49.5%) were treated with oFU (CapeOX + BV 42 pts/SOX + BV 5 pts). The pts characteristics between those were generally balanced except for PS 0-1 (72.9% in iFU/93.6% in oFU; p=0.012) and synchronous liver metastases (mets) (93.8% in iFU/78.8% in oFU; p=0.040). Adverse events ≥grade 3 were balanced except for leucopenia (25.0% in iFU versus 2.1% in oFU; p=0.002) and neutropenia (43.5% in iFU and 10.9% in oFU; p=0.001). Hand-foot skin reaction was not different between two cohorts. RR was 62.5% in iFU versus 71.1% in oFU (p=0.835). The median PFS was 8.3 months in iFU versus 8.2 months in oFU (p=0.835). Conclusions: The HGCSG0802 could be a database to investigate first line BV for mCRC in clinical practice. As a result of this analysis, in Japanese daily practice, efficacy was no significant difference between infusional FU/OX and oral FU/OX, and the profiles of adverse events varied from each regimens.