  In recent years tetraquark and pentaquark states have received much attention
due to the significant experimental findings. In this work masses of some heavy
tetraquarks are estimated by considering the spin-spin interaction, the
dipole-dipole interaction, and the meson-meson interaction. It is found that
such interactions give significant mass contributions. The Regge trajectory of
X(3872) state is also studied and is found to be non-linear. Masses of some
tetraquark states are also proposed.
