Complete solutions of Altarelli-Parisi evolution equations in leading order and structure functions at low-x

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.