Yes, for example with this code:
MakePlot[{\[Alpha]_, \[Beta]_, \[Gamma]_}, {a_, b_, c_}, h_, max_Integer] := Module[{u, if},
f[{x_, y_, z_}] := {z + (y - \[Alpha])*x, 1 - \[Beta]*y - x^2, -x - \[Gamma]*z};
u[0] = {a, b, c};
Do[u[n + 1] = u[n] + h*f[u[n] + h/2*f[u[n]]], {n, 0, max}];
if = Interpolation[Table[{n, u[n]}, {n, 0, max/h}]];
ParametricPlot3D[if[t], {t, 0, 2000}]
]
You can do this:
plot1 = MakePlot[{0.9, 0.2, 1.2}, {1, 3, 2}, 0.1, 200]
plot2 = MakePlot[{0.9, 0.2, 0.4}, {1, 3, 2}, 0.1, 200]
And then combine them:
Show[{plot1, plot2}]