How can I deselect entire edge loop in blender 2.8?

Shift+Alt+L/R click should work.  Sometimes, you have to hit just the right spot.  It's worked for me in 2.8.  

korneisgibnev098 I found in blender 2.8 if you turned on the “emulate” tablet pen mode that edge loop selection ends up being a double click of the mouse on an edge loop. I think shift + double-click mouse deselects. The shift + alt + click won’t work with the emulator on.

If that is not enabled then edge deselect mode is truly the Shift + Alt + ActiveMouseClick. (Do it once to add an edge loop to your current selection, do it again to deselect an already selected loop.)

Also keep in mind the “Selection Tool Settings” (can be found in View >> Tool Settings) might possibly be selected to the non-standard option (normally set to “Set a new selection” and has a image of a dashed box.

You also want to make sure that while in edit mode that the Toolbar (hotkey T) is set to “Select Box” mode which is used for selecting. It has a similar icon of a dashed box and and arrow typically. You can cycle through selection modes using the Q hotkey. I usually have mine set to the standard select (options are standard, loop select, circle select, and move-select)

the program is semi intuitive and only works with all quad geometry though. I have found edge loop deselection works best in “Edge Select Mode” but it is also intuitive for “Vertex Select Mode” so long as you select the loop’s line that is closest to a vertex but parallel with the loop.

the program is semi intuitive and only works with all quad geometry though. I have found edge loop deselection works best in “Edge Select Mode” but it is also intuitive for “Vertex Select Mode” so long as you select the loop’s line that is closest to a vertex but parallel with the loop.

hopefully something in my rambling works for ya!

Thanks for your reply! In fact I had emulate 3 mouse button on and because of that I wasn't able to deselect edge loops with Alt+click. Today I disabled this option and now it works perfectly! Thank you!

Awesome. Looks like emulate either mouse option causes separate behavior from the default. I am sure the devs were trying to be helpful. Just makes it difficult when you don't know what helpful additions they did haha.

All the same I am glad that you figured it out.