Voting system is according to age or educational qualifications comment on this?

Nice grammar. I can't tell if you're asking how it is, or how it should be.

In the U.S. (since you didn't bother mentioning country), voting is allowed at 18.

We have some real idiots, who have advanced degrees, so education shouldn't be the factor for the right to vote.

The bigger problem, imho, is that representative government doesn't work. You must always choose the candidate who agrees with the issues that are most important to you, even though they disagree with other issues that are important to you. We have the technology -- we no longer need representatives -- laws can be proposed through the initiative process (like 23 states currently allow), and then voted on by the people. I'm especially tired of elected officials giving themselves pay raises.