Abstract: Objective: To ensure the security of clinical blood transfusion by analyzing the causes of substandard filling of blood transfusion application forms. Methods: Two thousand eight hundred and sixty-four transfusion application forms collected from our department during Jan. 2009 to Dec. 2009 were checked and analyzed;integrity and standard filling of all the items were regarded as qualified forms. Results: One thousand two hundred and thirty-three (43.1%) of the transfusion application forms were substandardly filled,and 1 538 unstandard handwriting errors were detected. Conclusions: Substandardly filled transfusion application forms are frequently seen,which may be hidden danger to transfusion safety and lead to health disputes. It is necessary for medical workers to fill the transfusion application forms correctly to ensure the security of clinical blood transfusion.