Look at this example
%---------Example---------------
t=0:0.1:10;
y=[sin(t);cos(t);t.^2];
for k=1:3
subplot(1,3,k)
plot(t,y(k,:))
end
%---------------------------
h=findobj(gcf,'type','axes')
n=6 % numbers of ticks
for k=1:3
a=get(h(k),'xlim')
xt=linspace(a(1),a(2),n)
set(h(k),'xtick',xt)
end