I am working on BlackBerry user interface. But the BlackBerry UIs are less attractive compared to Android UI. I want to make my BlackBerry UI more attractive like in Android.
@Dave Markle is right, this is a fairly general question. Assuming that by 'attractive' you mean 'UI Controls that look better than the default' then you'll have to do a lot of custom control work. More an more in the BlackBerry industry it seems that leading applications are doing almost entirely custom UIs.
I won't touch on specifics of graphic design, that seems outside the scope of SO, but a good place to start is to get a graphics designer to put together some conceptual screens, and then as a developer your job will be to build controls to match that.
There are some tutorials on the net about how to get started with that. I've written a few - "BlackBerry UI - A simple custom field" is a good basic introduction on how to make a custom control.
And a correction to @Dave's comment - you can antialias text on the BlackBerry - though it's not well documented. For example, a 9 pt subpixel antialiased bold font, derived from the default system font:
Font.getDefault().derive(Font.BOLD, 9 Ui.UNITS_pt, Font.ANTIALIAS_SUBPIXEL, 0);