i have done MBA From Pakistani university(Lowest ranking university in world), I have 5 year Banking experience as Banking Services Manager and total 7 year experience in Finance.
I want to do MBA from Top Business School, can i got admission with having already MBA? currently I am earning low salary 5500 $ Annually ,but top business school MBA getting more than 5500 $ salary monthly.

Guide me and tell me about better school .

Ezra has answered part of this question at: http://board.find-mba.com/general-forum/insead-vs-cambridge-vs-hec-paris-42669?_ga=1.120997832.1982599738.1410115952 Indeed, people with pre-experience MBAs can be admitted to top business schools if they can convince the admissions teams that the two degrees are substantially different. So you can get into MBAs, and even more easily into master of science degrees, at these schools.

If you want to do another degree in business, then I suggest you work on your GMAT score and also work out what your career goals are. Then pick the schools which are most likely to get you those outcomes. Take a look at:-
GMAT Tiers - strong schools for your GMAT www.find-mba.com/board/27082
How to use LinkedIn to find the best school www.find-mba.com/board/33571

thanks Ducan,
i have two goals,

1) start with good salary after MBA
2)Better growth in career

Okay, well the easiest way to do that will be to stay in banking and finance. Do you want to stay in Pakistan? Maybe a Masters in Finance degree would be a good way forward: London, Cambridge and Singapore look interesting... http://rankings.ft.com/businessschoolrankings/masters-in-finance-post-experience-2015

if i stay in Pakistan after MBA ? than what is expected salary in Pakistan after doing MBA from top business school?
where MBA start in Jan 2016?

You can answer these questions yourself using google. Try Which schools start when http://www.find-mba.com/board/41131

At LUMS, average monthly MBA salaries were PKR 85,000 - around double your current salary - in 2011 http://lums.edu.pk/uploads/publications/pdf/19.pdf

Also see: http://tribune.com.pk/story/306761/was-that-mba-worth-it/

Duncan these salaries are MBA who done from Pakistani universities.
i want to know salaries done MBA from Top business school .

You can see the averahe annual salaries from top business schools by looking at the rankings; but for those salaries you would need to work outside of Pakistan.