Abstract: Aim The effect of polysaccharide of spirulina on mouse myelosuppression induced by cyclophosphamide was studied. Methods Mice in the model, treatment groups I and H were given cyclophosphamide (ip 100 mg·kg^-1) for there days. At the same time mice in the treatment groups I and II were given ig spirulin 30 mg·kg^-1 and 60 mg·kg^-1 for ten days, while mice in the control group and model group were given ip 20 mg·kg^-1 of NS. Peripheral blood and marrow cytometry, micromcelsus and chromosome aberration were analyed. Results In the dosages of 30 and 60 mg·kg^-1 polysaccharide of spirulina the polysaccharide of spirulina had perfect action on the perihem ateikon and the function of bone hematoplast induced by cyclophosphamide (P＜0.01) and antagonistic action on increase of bone cell micro nuclsus(P ＜0.05); The ratio of chromosome aberration in the treated group was lower compared with that in the model group. The inhibitory ratio was 51.2% and 62.5% in the treated groups I and II. Conclusion Polysaccharide of spirulina can perfect the hematoplast function of mice injured by cyclophosphamide.

Key words: polysaccharide of spirulina, myelosuppression, cyclophosphamide, micronuclsus, chromosome aberration