Brachionus calyclfurus(Rotatoria)were cltured on single alga Chlorella pyrenoidosa, Oocystls elliptica, and mixed at densities of 0.25.0.5, 1.0.and 2.0×10⁶>.celis/mL, respective-ly.Experiments were conducted at 25℃ in a photoperiod(LD18:6)with light intensity about 4000.lx.The results show that the average values of eggs produeed in medium of Chlorella pyre-noidosa were 6 00.6.75, 11.20.and 11.40ind..respectively.The percentages were 23.06%.22.41%-8.52% ad 4.85%.respectively.The mean eggs increased and the percentage de-creased with the increases of food concentration.The mean eggs were 3.33, 3.33, 2.33, and 3.83ind.in medium of Oocysti elliptica,the percentages were 36.11%, 30.55%, 20.83% and 12.50%, respectively.The mean eggs per female cultured on mixture medium (mixed Chlorella with the same quantity Oocystis)were 5.00, 4 67, 3.67 and 4.67 ind..respectively.The percentages of mic-tic females were 28.90%, 25 00%, 16 67% and 0%, respectively.When rotifer growing on medium of chlorella at densities varied from 0.125×10⁶>.to 8×10⁶.cell/ml, the mean eggs increased gradually from 4.17ind.to 13.67ind., and the percentages of micticfemales decreased from 32.00%.25.00% to 4.48%.In range of 4.0×10⁶.to 8.0×10⁶.cells/ml,, the mean eggs decreased to 8.33 ind.(8.0×10⁶.cells/mL excluded)and the Percentage of mictic fem ale incread to 48.O0% again.The correlation between mictic percentage(Y)and concentration of fod(X)was signifi.cantly negative in medium of Oocystis(r=-0.97).and in mixture(r=-0.99).the equation of regression y=37.3148-13.1348X (in medium)and Y=33.1778-16.5683X (in mixture).