In this talk, I will report some recent researches on the asymptotic behavior of singular values of some operators on a large class of weighted Bergman spaces, including Toeplitz operators, Hankel operators and composition operators. We use the non-increasing rearrangement of IDA function with respect to a suitable measure to characterize the asymptotic behavior of the singular values sequence  of Hankel operatorsacting on a large class of weighted Bergman spaces. As a corollary, we show that the simultaneous asymptotic behavior of  and  can be characterized in terms of the asymptotic behavior of non-increasing rearrange-ment of mean oscillation function. Moreover, in the weighted Fock spaces, we demon -strate the Berger-Coburn phenomenon concerning the membership of Hankel opera-tors in the weak Schatten class.