In my chart, Incomprehensible what value of Y axis belong to X axis, what the best way to present the chart clearly. Attached Image.
Have you considered using StripLines?
Taken from this MSDN article
To show vertical strip lines, right-click the horizontal chart axis and click Horizontal Axis Properties.
Select the Use interlacing option. Grey strip lines will appear on your chart.
Applying this to a chart will then alternate the colour for each category on the X axis, such as this. This will make it clearer which columns belong to which X axis category.
Update
For use with a 3D Clustered column chart you will need to set up the Striplines in a more complicated way.
Select your X axis and find StripLines in the properties. Hit the '...' to open a new window.
Add a New Member and set it up as shown in the below image. This is effectively saying show a line for every second number, and offset the stripline by 0.5 of a category.
In my example I have set the BackgroundColour to MidnightBlue also, which gives an output similar to
With this alternating background it should make it clearer for your users to see which columns belong to which category.
Let me know if you need further assistance with this.