Objective To study CD64 expression in neutrophilic granulocyte and its clinical effect in neonatal infection disease. Methods CD64 was detected among 59 neonatal patients(septicemia group 34 patients, local infection group 25 patients)hospitalized in our neonatal department diagnosed as neonatal infection disease in 48 h after hospitalized,2 weeks after therapy, then the results were compared with 27 patients as non - infection disease during the same period. Results CD64 in septicemia group was (6156. 21?3643. 32) molecula per cell,in local infection group was (2176.19 ? 946. 32)molecula per cell, in non- infection group was (2176. 19 ? 946. 32) molecula per cell.There were significant differences among three groups (all P0.05). Conclusions CD64 expression increases in bacterium infection disease. It is more obvious in widespread infection desease.and it can be the mark in early diagnosis of neonatal infection disease.