Me and my ex husband had been divorved for 5 years, but have reconciled. 6 years ago he was convicted for check fraud. he was sentenced to 3 years imprisonment but only served 7 months. he was released on good conduct. He is a professional, a teacher. He has just finished his masters degree and is persuing his PHD. Me and my 2 kids are permanent residents of US. Will it be difficult to bring him over here since he has this record? does this make him inadmissible though he did not kill anybody?

He will need a waiver, see the waiver forum further down. Called a CIMT, Crime involving Morale Turpitude.

But probably not the biggest delay.

Have you filed for him, if so when?

When can you apply for Citizenship? Or if you do not know that, what is the date of issuance of your Green Card.

No I have not filed for him, somebody told me that it will take longer if I file for him as a green card holder. My green card was issued 2 years ago. Do I have to wait for 3 more years and become a US citizen.

You can file now an uipgrade your petition when you Have Citizenship.

Protects you in case there is some problem getting Citizenship.

The interview will be 4 or 5 years down the road, and a longer period to have chown good subsequent charachter.