The leukaemia is one of the familiar hematic disease.At present,it has ccountted for about five percents of national patients with malignant turmor taken bad,mostly for child and young.The hospital diagnoses leukaemia mostly by hemogram and cytochemistry but the patients suffer the much pain.If we apply spectroscopy to diagnose leukaemia,the patients will get less pain.In this article,we can differentiate the normal and malignant serum of leukaemia by the statistic and analysis of absorption spectrum′s datum after their serums are detected by spectralphotometer.And it provides the doctor a new thought for quickly diagnosing leukaemia without hurt.