The "new immigrants," who in the last 10 years have come to the United States from Cuba, Mexico, Cambodia, Korea and Vietnam, are being exploited by their fellow countrymen who came here before them, according to new studies.

"In many cases, the new immigrants are given jobs inside their ethnic communities," Dr. Edna Bonacich of the University of California at Riverside told a press conference today at the 145th national meeting of the American Association for the Advancement of Science. "But the jobs pay very low wages and involve working in some real sweatshops," she said.

Sociologists studying immigrants who have come to the United States since the immigration laws were liberalized in 1965 found thatmany were better off working for native American employers than for employers who shared their heritage.

A study by Dr. Robert L. Bach of the State University of New York at Binghamton found that Cubans and Mexicans who found jobs outside their ethnic communities were paid more than those who chose to work for Cuban, and Mexican employers.

"Mexicans who are employed by white Americans made $142 a month more than their counterparts in ethnic jobs," Bach said. "Mexicans who worked in firms hiring mostly white Americans where they were minorities made $155 a month more than their counterparts," he said.

Bach followed 822 Mexican men and 592 Cuban men who came to the United States in the fall of 1973 and the spring of 1974. His study was financed by the National Science Foundation and the National Institute of Mental Health.