The quasiparticle model is improved by the free magnetic contribution to
investigated the QCD matter in a strong magnetic field. The
temperature-dependent bag function is determined by the thermodynamic
consistency to represent the difference in energy density between physical
vacuum and lowest state of QCD. It is found that the positive bag function
vanishes at high temperature indicating the deconfinement. The rapid decrease
of the bag function in stronger magnetic fields reveals the so-called inverse
magnetic catalysis. The interaction measure at high temperature remains so
large that the usual Stefan-Boltzmann limit can not be reached. We suggest a
limit β£qiβBmββ£T2/4 for each landau level pressure. Finally, it is
demonstrated that the positive magnetization modified by the bag function and
free magnetic contribution indicates the paramagnetic characteristic of QCD
matter.Comment: 8 pages, 6 figures, accepted for publication in PR