Hi Jian,
thank you for your answer.
For this occasion I a little bit modified file
arcgis_js_api\\library\\3.0\\jsapi\\js\\esri\\tasks\\PrintTask.js.uncompressed.js
and I am using this one.
I just added one "if" code
if (gLayer.graphics[idx].visible) {
}
into method _createFeatureCollection
I will happily use original library file after fixing this problem.
Thank you
Milan Schmidt