The ground-state deformations and B(E2) values of Ne and Mg nuclei around N=20 are studied within the iramework of the macroscopic-microscopic(MM) model with isospin-dependent Nilsson potential.The calculated results are compared with those obtained from standard Nilsson parameters and with experimental ones.It is found that the calculations with new Nilsson parameters well reproduce the experimental large deformations and B(E2) values for Ne and Mg nuclei around N=20.The N=20 shell closure of Ne and Mg isotopes disappears in the MM model and this agrees with experimental data.