The experimental results on the multiplicity distribution of the different particles produced from the interactions of {sup 7} Li with emulsion nuclei at 3A GeV/c are reported. A comparison with data on collisions induced by nuclei at nearly same momentum per nucleon is presented in order to reveal the dependence on the projectile mass. The internal structure of {sup 7} Li is investigated by studying the projectile fragment. The average multiplicity of shower particles< n {sub s}> induced by {sup 7} Li is found to be less than that by {sup 6} Li. Angular distributions of target fragments and relativistic charged secondaries have been investigated. No shock wave phenomenon is observed. Forward-to-backward ratios in each case are calculated. A detailed study of probability distributions of relativistic secondaries produced per unit rapidity as well as rapidity densities and their dependence on projectile and target mass has been carried out. The comparison of angular spectra of shower particles produced in central and peripheral collisions provides the support for the limiting fragmentation hypothesis. The collisions seem to become more central with increasing shower-particle multiplicity.