Manganese ions implantation into ultrapure GaAs layers grown by molecular beam epitaxy were investigated by photoluminescence technique systematically in a wide range of manganese concentration up to 1×1020cm-3. Five shallow emission bands denoted by (Mn°, X), 'G', 'G'' 'H' and (D, A)2 are formed in the implanted layers in addition to the well known Mn impurity related emission at approx.880nm. With increasing manganese concentration to 1×1019cm-3, 'G' exhibits no energy shift, suggesting that 'G' is different from the behavior of [g-g] emission that is commonly formed in shallow acceptor (such as C) incorporated ultrapure GaAs. (Mn°, X), 'G' and 'G' present no energy shift with increasing excitation intensity, while 'H' and (D, A)2 indicate peak energy shift greatly showing typical donor-acceptor pair characteristics. 'G' and (Mn°, X) are found to hold similar radiative origin which is different from 'G'. Temperature dependence measurement reveals that emission 'G has a thermal activation energy of 5.4 meV.