網上找到的，供大家參考：
How much leeway do you have when you have received a job offer? What's the best way to make a counter offer? When should you stop negotiating and accept or reject a salary offer?
Answer: There isn't a simply answer, but employers aren't thrilled with candidates who go back and forth over salary offers multiple times. If it's not what you expect you can ask if there is any more flexibility in the starting (or future) salary or you could turn it down, realizing that there may not be another counter offer. Also, there may be a set salary range for the position and there may not be much room for further negotiations.
One of the best ways to open discussions after you have received an offer is to ask for meeting to discuss the offer. Review a counter offer letter and counter offer email message you can tailor to fit your circumstances if you're going to make a counter offer.
Given the competitiveness of the job market, the high unemployment rate, and the number of qualified candidates for open positions, be careful about over-negotiating. Research your value, research the job and the company, and if you are comfortable with the offer, I wouldn't push too hard to get a little more, just because you might be able to.
