There is a way. Change the drawing order of objects in the graph so that the bars are drawn on top of the negative error bars, hiding them.
-Create your graph with error bars
-right-click in the graph and choose "Customize..."
-Click on the "Error Bar" item in the selection list, then click the up arrow button to move it up in the drawing order before "Bar".![11801_Graph Builder.png 11801_Graph Builder.png](https://community.jmp.com/t5/image/serverpage/image-id/3244iFB9FE0454EEA54EF/image-size/medium?v=v2&px=400)