Can a tape conversation between two people be use as evidence in cicurit court without the other person knowing he or she is been recorded

It depends on the state. In most states a taped confession, or admission is not admissible if the other party had no prior knowledge. That being said, if you were in the act of committing a felony, the tape may be used against you. Please contact an attorney for more information.

I realize you are new "here" and are trying to help BUT without knowing where the OP is it is impossible to give an accurate answer.

"Many" and "most" and similar statements are not helpful. NY (where I am) is just one of the States that allows a taped conversation to be admitted as evidence when only one party is aware of the taping.

The tape either is legal or not legal - your answers appears to suggest a little of each.

To OP - where are you?

It depends on the state. In most states a taped confession, or admission is not admissible if the other party had no prior knowledge. That being said, if you were in the act of committing a felony, the tape may be used against you. Please contact an attorney for more information.

Wrong yet again. In 38 of the 50 states only one party of a phone conversation needs to consent. Summary of Consent Requirements for Taping Telephone Conversations (http://www.aapsonline.org/judicial/telephone.htm)

Who were the two people talking, did one of them do the taping or some 3rd party. What state, was this a telephone conversation or a recording of a live person to person conversation?