Using the archive data from the Rossi X-ray Timing Explorer ({sl RXTE}), we have studied the evolution of the X-ray profile of the Crab pulsar in a time span of 11 years. The X-ray profiles, as characterized by a few parameters, changed slightly but significantly in these years: the separation of the two peaks increased with a rate $0.88pm0.20,textordmasculine$,per century, the flux ratio of the second pulse to the first pulse decreased with $(3.64pm0.86)times10^{-2}$,per century, and the pulse widths of the two pulses descended with $1.44pm0.15,textordmasculine$, and $1.09pm0.73,textordmasculine$,per century, respectively. The evolutionary trends of the above parameters are similar to the radio results, but the values are different. We briefly discussed the constraints of these X-ray properties on the geometry of the emission region of this pulsar.
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