This is my coding :
file11='XA20120601.txt';
[d11(:,1), d11(:,2), d11(:,3), d11(:,4)]=textread(file11, '%f%f%f%f', 'headerlines', 5);
file12='XB20120704.txt';
[d12(:,1), d12(:,2), d12(:,3), d12(:,4)]=textread(file12, '%f%f%f%f', 'headerlines', 5);
figure(1);
grid on
plot(d11(:,1),d11(:,2),'r')
hold on
plot(d12(:,1),d12(:,2),'b')
xlabel('Time (s)')
ylabel('Acceleration(g)')
legend('Original Accelerogram','Matched Accelerogram')