We report on a 40 ks Chandra  observation of the TeV emitting high mass X–ray binary HESS J0632+057 performed in February 2011 during a high-state of X-ray and TeV activity .
We have used the ACIS-S camera in Continuos Clocking mode to search for a possible X-ray pulsar in this system .
Furthermore , we compare the emission of the source during this high state , with its X-ray properties during a low state of emission , caught by a 47 ks XMM–Newton  observation on September 2007 .
We did not find any periodic or quasi-periodic signal in any of the two observations .
We derived an average pulsed fraction 3 \sigma upper limit for the presence of a periodic signal of \buildrel < \over { \sim } 35 % and 25 % during the low and high emission state , respectively ( although this limit is strongly dependent on the frequency and the energy band ) .
Using the best X-ray spectra derived to date for HESS J0632+057 , we found evidence for a significant spectral change between the low and high X-ray emission states , with the absorption value and the photon index varying between N _ { H } \simeq 2.1 - 4.3 \times 10 ^ { 21 } cm ^ { -2 } and \Gamma \simeq 1.18 - 1.61 .
At variance with what observed in other TeV binaries , it seems that in this source the higher the flux the softer the X-ray spectrum .