  We present comlete solutions of singlet and non-singlet Altarelli-Parisi (AP)
evolution equations in leading order at low-x. We obtain t-evolutions of proton
and neutron structure functions and x-evolutions of deuteron structure
functions at low-x from AP evolution eqiations. The results of t-evolutions are
compared with HERA low-x and low-Q^2 data and those of x-evolutions are
compared with NMC low-x and low-Q^2 data. Also we compare our results with
those of general solutions of AP evolution equations.
