Something like this perhaps
x = 0:0.1:6;
y1 = sin(x);
y2 = sin(2*x);
y3 = cos(x);
y4 = cos(2*x);
subplot(2,2,1)
plot(x,y1)
t = axis;
text(t(2),1.2*t(4),'Title1')
subplot(2,2,2)
plot(x,y2)
subplot(2,2,3)
plot(x,y3)
t = axis;
text(t(2),1.2*t(4),'Title2')
subplot(2,2,4)
plot(x,y4)
You will have to adjust the multipliers in the text commands to suit your own plots.
