Harper's, Science '82, Life and The American Lawyer are among the winners of the 18th annual National Magazine Awards, announced yesterday in New York.

The National Magazine Awards, established in 1965 by the American Society of Magazine Editors and now considered the most prestigious in the industry, are assisted by a grant from the Magazine Publishers Association and administered by Columbia University Graduate School of Journalism.

The winners, chosen from a field of 59 nominees, were announced during a luncheon at the Waldorf-Astoria by Midge Richardson, editor of Seventeen, and Osborn Elliott, dean of Columbia's graduate journalism school, before a record audience of 770. Each winning magazine received a bronze plaque and a copy of an Alexander Calder stabile titled "Elephant."

Eleven magazines were cited in eight categories: General Excellence (ranked by circulation): Over 1 million: Life, "for its wonderfully varied and skillful blend of words and pictures, which captures the world in all its anguish, splendor and humor--and honors a great tradition of magazine journalism."

400,000 to 1 million: Science '82 (published here by the American Association for the Advancement of Science), for "its superior combination of versatility, good writing and editing and effective graphics."

100,000 to 400,000: Harper's, "for exploring subjects of serious intellectual content and lasting value, and writing about them with skepticism, verve and humor."

Under 100,000: Louisiana Life, for "a masterful weave of design and content." Essays and Criticism: The American Lawyer, for the "Headnotes" column by editor Steven Brill, "who performs the extraordinary feat of analyzing issues of great complexity and great public importance with wit, style and utter lucidity." Public Service: Foreign Affairs, for the article "Nuclear Weapons and the Atlantic Alliance" by McGeorge Bundy, George F. Kennan, Robert McNamara and Gerard Smith, advocating no first use of nuclear weapons in defending against aggression in Europe. Single-Topic Issue: IEEE Spectrum (a technical journal published by the Institute of Electrical and Electronics Engineers) for "Technology in War and Peace," an overview "of the world's weaponry and where it is taking mankind." Reporting: Institutional Investor (a New York monthly for investors and financial professionals) for Chris Welles' "Drysdale: What Happened?," an account of how behind-the-scenes investment transactions threaten the health of the economy. Design: New York, for overall visual effect. Fiction: The North American Review (a quarterly from the University of Northern Iowa) for three stories: "Scales" by Louise Erdrich; "Putting and Gardening" by William F. Van Wert; and "Novitiate" by Erica Liederman. Service to the Individual: Sunset (a how-to monthly covering life in the West) for "Fish Market Revolution," cited as "an editorially unconventional guide to shopping and cooking."