We assign a new spin of magnitude one to the basic particles (quarks) in the SU3 theory and assume, between quarks (or between antiquarks), a two-body force depending on this spin which is attractive for triplet and repulsive for singlet and quintet states. This force leads to the saturation in the three quarks (or three antiquarks) system and, when we assume the S state for baryons, it gives the values of their (ordinary) spins i. e. 3/2 for decuplet baryons and 1/2 for octet baryons. In this case, the singlet baryon cannot exist in the S state. We consider that mesons are composed by baryons by another kind of force which is weaker than the above mentioned one and attractive only between a quark and an antiquark.