<正> The types of DNA content ean be divided into four groups:（1）diploids andnera-diploids;（2）triploids;（3）tetraploidy and hyperploidy aneuploids;（4）biclonal DHAcontent.Recent studies show that measuring DNA content by flow cytometry（FCM） can beapplied to most primary bone lumors in pointing out clinicatly relevant informattons.Ii thisstudy

cellular DHA content of 33 primary bone tvenors was analysed by FCM Isolated ratcle-ar suspensions were prepared by a simple

rapid and effective method using 10％ formatin-fctedand paraffin-embeuded bone tumor specimens.The results showed that 10 benign（inchtding 5Grade I giant cell tumors of bone） and 5 histologically questionable tumors had nornufl DNAcontent （diploids or near-diploids）and the other 7 questionable and of the 11 malignanttumors had abnormul DNA content（aneuploids）.The cell cycle distribution analysis showedthat the aneuploidy tumors had higher proponion of S-phase and G2+M-phase cells than the nor-mal ploidy tumors

indicating there were differences in proliferative activity.The method alsoshowed that beniga and low-malignant primary bone tumors were diploids or near-diptoids

andhigh-malignant cnes were aneuploids Compared with typically pathological grading

the flowDNA analysis of bone tumors can more objectively point out their biological behavior andprognosis.