Objective Toevaluate nucleated red blood cell screening using the Sysmex XE-2100 blood cell analyzer. To analyze positive expected value and negative expected value about the alarm of nucleated red blood cells. And to evaluate the sensitivity and specificity of Q-flag result in a certain range. Methods With manual microscopic examination as the gold standard to recheck 103 cases of Sysmex XE-2100 NRBC alarm (100≤Q-flag≤300) samples and 105 cases of no alarm (Q-flag＜100) samples. Results When 100≤Q-flag≤200, the positive expected value was 48%. When 200＜Q-flag≤300, the positive expected value was 81%. When Q-flag≥100, the positive expected value was 60%. When Q-flag＜100, the negative expected value was 86%. Conclusions Sysmex XE-2100 blood cell analyzer NRBC alarm has high sensitivity and specificity, but there are some interfering factors. The positive expected value of the alarm is associated with the interval about Q-flag value.