Abstract: Biochemical compositions and physiological functions of froth that Monopterus albus spits in breeding seasons were reported in this paper.The results showed that the viscosity of the froth was 2.72 mPaS,the froth was glycoprotein,and the content of sugar was 0.156 mg/mL,that of protein was 0.250mg/mL.The ratio of protein to sugar was 1.60. The froth protein was composed of four compositions by SDS-PAGE.The molecular weight of the froth protein was 42.5kDa,58.6kDa,65.3kDa,and 98.2kDa,respectively. It consisted of 16 kinds of amino acids,the total contents of amino acids was 201.88 mg/100mL.At the same time,physiological functions of the froth were analysed and discussed.The physiological functions of the froth included three aspects.Firstly,the hatching rate of oosperm was 76.0%,96.7%,94.2%,and 64.0%at different water temperatures(22℃,25℃,28℃,and 31℃)in the froth groups,respectively,and the hatching rate of oosperm was 22.8%,33.9%,30.2%,and 14.6%in the control groups,respectively.Secondly,the froth could decrease the water mold growth,and prevented oosperm from infecting the water mold.The frequency of the oosperm infected by water mold was 0.0%,2.1%,8.4%,and 12.5% at different water temperatures in the froth groups,respectively,and the frequency of the oosperm infected by water mold was 44.8%,65.4%,82.0%,and 90.5% in the control groups,respectively.The average frequency of the oosperm infected by the water mold was 5.75% in the froth groups,the average frequency of the oosperm infected by the water mold 70.83%in the control groups.Finally,the froth could increase oxygen,and accelerate velum of oosperm cracking.Comparison with effect of different hatching methods on the hatching rate and survival rate of the ricefield eel.The hatching and survival rate of the ricefield eel from high to low was found by the froth incubationthe dripping water incubationthe sleeping water incubation.