I am not a stable person. I change my job per one/two year.

In middle age, employer will value your job experience more than your qualification. I think you are a stable person as you stay in the audit field for 15 years.
Anyway, it will not be easy to change a job, especially you don't have commercial experience. Whether the past decision was right or wrong is irrelevant, you need to face the future.
Suggest you to stay in your present job until you find a better one.

I want to switch to commercial side. But I only have small local firm exposure. I am a non-accounting graduate.
Since 30's, I don't have any interview from commercial side. In Hong Kong, a non-accounting graduate can only work in small local firm.

You have a degree and is a qualified auditor. Yet in 15 years your salary increment is only 7.5k?

No, you shouldn't quit the job, HK nowadays is tough.
At time of 2006-2008, HK is booming, mind telling us why you don't switch to commercial like banks, or listed company?

Now, I am a ACCA member. I am 41 years old. I am a audit senior. The salary is 14.5k. Should I quit the job?

Now is 2010, with 14 years of experience, are you a group FC or partner now? If yes, the path is worse than working than in banks, but still can make a living (basic standard).

In 1996, I could only find a audit job whose requirement is F5 & LCC inter. The salary is 7K.

Yes, passby's question is exactly what I wanted to ask, you've been jobless for 14 years? If that’s a yes, I hope you haven’t spent the past 14 years blaming the market, employers, that bank, or you yourself in particular?

If you have, when and how are you going to let this nightmare ends? Your discontentment certainly won't help and will only drag you down if you keep on focusing on the negatives. What’s done is done. We can’t turn back time but we can change our outlook and our perspective on things.

After more than a decade, it’s time to move on. Care to tell us more?

1996 is 14 years back, you became unemployed since 1996 for 14 years?