Nearly three out of every four of the nation's top state and local prosecutors reject the Reagan administration's "zero tolerance" anti-drug policies as an important law enforcement tool and one fourth believe that marijuana should be decriminalized, according to a survey to be released Monday.

The survey by the National Law Journal also found that almost two thirds of prosecutors believe their efforts are having little or no impact in reducing the supply of illegal drugs or increasing their street prices."These people have never been asked these questions before and what they're saying is, `Hey, it's time to come up with some new ideas because what we're doing isn't working," ' said Tim Robinson, editor in chief of the New York-based legal newspaper.

The survey was based on telephone questioning of 181 chief prosecutors or their top narcotics deputies in every state - the officials who prosecute the bulk of the nation's narcotics cases.

The Justice Department several months ago began urging federal, state and local prosecuctors to "target" drug users as well as traffickers to demonstrate that no amount of drugs will be tolerated.