Abstract
Soft gamma repeaters (SGRs) and Anomalous X-ray Pulsars(AXPs) are regarded as the so called "magnetars", which are strongly magnetized neutron star. All spin-down period of the identified SGRs and AXPs have been found, except for SGR 1627-41. We present the results of periodicity search in the X-ray data of SGR 1627-41 observed by the BeppoSAX, ASCA and RXTE missions. Searches have been performed with the H-test and the method of epoch folding in the period range between 0.01 sec and 100 sec with period steps corresponding to one fifth of the Fourier width. We have found 5 significant periods in the 1998 August BeppoSAX observation. One of these features is at 0.019 sec, and the others are between 6 sec and 98 sec. These features are not found in later observations, during which the source flux was lower. To further investigate to verify of these periods, more observations, particularly during when will the source be in high state of the source, will be very helpful.