Fifteen hundred exceedingly diplomatic high school students from the U.S., Mexico and Canada will attend classes here today as delegates to the annual Harvard Model United Nations, which began yesterday in Boston.

George Varughese '77, president of the International Relations Council (IRC), which sponsors the program, said yesterday the model U.N. attempts to develop debating skills, personal diplomacy, and an understanding of the international system in participants.

Students are visiting the University today as part of the "Harvard Day" portion of the program, which includes optional attendance at several classes, Varughese said.

Delegates to the program represent the views of their assigned countries in mock meetings of the General Assembly, the Security Council and assorted economic and legal committees.

Barry J. Reed, a sophomore at Langley High School in McClean, Va., who is representing the People's Republic of China, described conference activities as "a lot of yelling."

Varughese said the IRC sponsors speakers, films and radio programs with council profits. A scholarship program is forthcoming, he said.

The IRC came under considerable scrutiny in 1975 when model U.N. funds financed several private dinners for the program's directors. Varughese said the IRC is now professionally audited, receives advice from three faculty advisors, and consults frequently with Archie C. Epps III, dean of students.