Myeloid Derived Suppressor Cell (MDSC) has been raised to be a novel target for multiple cancers. However, target agents on MDSC have not display promising efficacy. One of the critical reasons shall be less optimal patient selection. In the present study, we aimed to identify clinical parameters relevant to MDSC level in hepatocellular carcinoma (HCC) patients for future MDSC targeted therapy. In the present study, a series of 55 HCC patients (testing group) and 20 healthy donors were analyzed investigating frequencies of MDSC in peripheral blood mononuclear cells (PBMC). As a result, we found that MDSC level was increased in HCC patients compared to healthy donors (10.33% vs 1.54%, p < 0.0001). The monocytes (r2 = 0.2875, p < 0.0001), neutrophils (r2 = 0.3630, p < 0.0001) and platelet counts (r2 = 0.0828, p = 0.0331) in circulation was positively associated with MDSC level. Then, the prognostic value of the above predictors was determined in a retrospective database of 255 HCC patients (validation group). The baseline characteristics of testing and validation group were similar. Multivariate analysis by Cox regression revealed that neutrophil count was an independent predictor for overall survival (OS) (p = 0.000, HR 1.065, 95% CI 1.028–1.103), with the rest parameters failed to reach a significant result. In summary, the present study firstly identified blood neutrophil counts was a predictor of MDSC level in PBMC for HCC patients. And, patients with higher neutrophil count level might be the optimal patient subgroup for MDSC targeted therapy.