  We present new observations of two anomalous X-ray pulsars (AXP) 4U 0142+61
and 1E 1048.1-5937 made in 1998 with the ASCA. The energy spectra of these two
AXPs are found to consist of two components, a power-law and a blackbody
emission from the neutron star surface. These observations, when compared to
earlier ASCA observations in 1994 show remarkable stability in the intensity,
spectral shape and pulse profile. However, we find that the spin-down rate in
1E 1048.1-5937 is not constant. In this source, we have clearly identified
three epochs with spin-down rates different from each other and the average
value. This has very strong implications for the magnetar hypothesis of AXPs.
We also note that the spin-down rate and its variations in 1E 1048.1-5937 are
much larger than what can normally be produced by an accretion disk with very
low mass accretion rate corresponding to its low X-ray luminosity.
