hi all,
I am planning to buy a domain for my Business website, what should i consider to choose it. ??

I suppose you need to be more active and use search option on this forum. I suppose you will be able to find plenty of information here.

The main thing you should consider is tour domain should be your brand name and also
if you want better rank in google your domain should contain keywords you want to rank better for.

1. Brand name
2. A keyword if your brand name makes it more than 10 characters.

But, I doubt whether there would be any good domain names at present based on most of the keywords.

3. Also try to get a TLD based on your location. That is, if you are living in US, then choose .US and if you are living in UK and concentrating on UK locale, then choose .UK or .co.uk for more visibility.