An experimental study of the evolution of two-dimensional foam is presented
. The topological properties of two-dimensional foam as a function of the e
volution time were investigated, and the relationship between the topologic
al properties and stability of two-dimensional foam was discussed. In the e
volution of two-dimensional foam, two distinct states were observed: a tran
sient state characterized by the presence of ordered state and a long-term
fully disordered state. The long-term behavior of the foam shows that the a
verage bubble area increases as a power law with exponent a=1.5, which is d
eviated from Von Neumann law and the possible reasons discussed. In additio
n, the distribution of sides of bubbles and the second moment of the distri
bution of number of sides are also discussed.