The extended photometry available for XZ Dra , a Blazhko type RR Lyrae star , makes it possible to study its long-term behavior .
It is shown that its pulsation period exhibit cyclic , but not strictly regular variations with \approx 7200 d period .
The Blazhko period ( \approx 76 d ) seems to follow the observed period changes of the fundamental mode pulsation with { d } P _ { B } / { d } P _ { 0 } = 7.7 \times 10 ^ { 4 } gradient .
Binary model can not explain this order of period change of the Blazhko modulation , nevertheless it can be brought into agreement with the O - C data of the pulsation .
The possibility of occurrence of magnetic cycle is raised .