【Abstract】Objective To discuss the differences of Muc2 and DCN gene knockout mice on kronismus. Methods Knockout homozygote males and females (Muc2－/－,DCN－/－ ) were mated respectively according to 1:1 or 1:2. The 1-3 generation of average litter sizes ,parity time interval, and kronismus in Muc2 and DCN gene knockout mice were observed.Results An average litter sizes of Muc2 gene knockout mice are 5.80 + 0.95. the average birth time interval is 42.29 + 2.28 days; DCN knockout mice seed production on average 3.85 + 0.76, the average birth time interval is 24.86 + 10.42 days.Muc2 and DCN gene knockout mice in average litter sizes ,parity time interval, and kronismus are obviously different. Conclusions Two groups of knockout mice reproductive performance are different.It reveal may be associated with Muc2 and DCN gene.