How to save to KML or KML file using google maps. I can't find menu command like that. I'm working on China region.
Google changed the layout in early 2015 (February or March, I think, recently at the time of writing anyway).
You cannot save the background data (but similar data are freely available from OSM anyway). Your own points, lines and polygons can be saved to KMl/KMZ by clicking on the top-most three vertical ellipses (highlighted in red in the screenshot) in the map details window and selecting
Export to KML:
Alternatively, just work in Google Earth and simply right-click on your item or group of items in the My Places tree and choose
Save Place As.
If you are working collaboratively, it may be more practical just to share the map with named people and allow them to edit it, than to save the data and pass it around.