The taper modifier produces a tapered contour by scaling both ends of an object’s geometry; one end is scaled up, and the other is scaled down.
You can control the amount and curve of the taper on two sets of axes. You can also limit the taper to a section of the geometry.
Step1: Create a sphere
Fig. 130
Step2: click on modify tab and select taper
Fig. 131
Step3: specify taper axis and amount.
Fig.132