If either Interior Secretary James G. Watt or Veterans Administration chief Harry N. Walters decides that one of his aides needs to start carrying a gun and making arrests, he could authorize it.

Environmental Protection Agency Administrator Anne M. Gorsuch and Attorney General William French Smith can, too, but Labor Secretary Raymond J. Donovan can't and neither can most other Cabinet members.

The Justice Department said it doesn't keep an official list of which federal employes can carry guns and make arrests. But in 1975, the Congressional Research Service compiled one that now has been updated by the Senate Labor and Human Resources Committee. Here are some of the people who can:

* Library of Congress special police.

* Immigration and Naturalization Service employes authorized by the attorney general.

* Superintendents of national military parks and national cemeteries.

* All justices, judges, magistrates, or any chancellor, judge of a supreme or superior court, mayor of a city, justice of the peace or other magistrate of any state.

* Interior's chief special officer for the suppression of liquor traffic among Indians.

* Secret Service agents.

* Harbor superviser, inspectors and deputy inspectors of the New York, Hampton Roads and Baltimore harbors.

* Sergeants-at-arms of the Senate and the House.

* Agriculture Department tick riders who patrol border areas to prevent the illegal importation of animals that may be infested with ticks.

* Department of Agriculture employes who investigate food stamp fraud.

* Superintendent, caretakers and rangers of the Lake Mead National Recreation Area.

* Designees of the secretaries of Interior, Treasury and Commerce who protect endangered fish and wildlife, wild horses and burros, the Bear River migratory bird refuge, the Upper Mississippi River Wildlife and Fish Refuge and marine mammals; employes responsible for enforcing the migratory bird treaty and the Northwest Atlantic Fisheries Covention.

* Capitol police.

* Special police at the Government Printing Office.

* Persons authorized by the president.