By using spaces IDA and -estimates, we characterize boundedness, compactness of Hankel operators on weighted Fock spaces in Cn. As an application, for bounded symbols, we show that the Hankel operator Hf is compact if and only if  is compact, which complements the classical compactness result of Berger and Coburn. We also apply our results to the Berezin-Toeplitz quantization.