  We investigate the properties of dibaryons containing u and d quarks in the
constituent quark model. In constructing the ground state wave function, we
choose the spatial part to be fully symmetric and the remaining color, isospin
and spin part to be antisymmetric so as to satisfy the the Pauli principle. By
adapting the IS coupling scheme that combine the isospin basis function with
the spin basis function, and subsequently coupling this to the color singlet
basis function, we construct the color $\otimes$ isospin $\otimes$ spin states
compatible with the physical states of the dibaryon. By using the variational
method, we then calculate the mass of the dibaryon in a nonrelativistic
potential model, involving Coulomb, color confinement and color-spin hyperfine
interaction. In particular, to asses the stability for different types of the
confinement potential, we introduce one that is linearly proportional to the
interquark distance and another to its square root. For all cases considered,
we find that there are no compact bound states against the strong decay.
