The District of Columbia ranks second in a nationwide tally of the number of public employes per 10,000 residents and pays its employes the second highest salaries in the country, according to a Census Bureau report on government employment released yesterday.

Alaska is first in both categories in the report, which lists numbers of full-time state and local workers per 10,000 residents as of October 1984 and the average full-time pay in that month for each state's and the District's public employes.

The total number of state and local employes in each jurisdiction is higher than the figures given, because of part-time workers.

The District listed 762.9 employes per 10,000 residents, with an average monthly pay of $2,338, while Alaska listed 793.1 and $2,958.

Wyoming ranked third in the in the ratio of employes to residents, with 677.2, and paid them an average of $1,805 a month.

D.C. officials have always been sensitive about surveys that show the city's work force as disproportionately large, arguing that no other U.S. city or state jurisdiction fairly can be compared to the District.

"We are . . . unique in the United States, we are totally urban, 100 percent," City Administrator Thomas Downs said yesterday, explaining the high demand for government services here. "States balance out by the lack of government employment in rural areas. There is not a square foot of rural [area] in the District of Columbia."

In states such as Alaska and Wyoming, however, the presence of a small population spread over a large land mass is the chief cause of the high ratio of public workers per resident, according to Meredith De Hart, a social science analyst for the Census Bureau.

The District employs about 39,000 full-time workers, or about one for every 16 of its 622,823 residents. The average annual salary for union and nonunion D.C. employes, nearly half of whom are women and about 75 percent of whom are unionized, was $21,442 as of January 1985.

Relatively higher government employe salaries usually are linked to higher costs of living, according to De Hart.

"When you get into an urban area like the District, you get higher salaries," she said, adding that Alaska also has a high cost of living.

The Census Bureau report showed California with the third highest average monthly salaries, at $2,263, followed by Michigan and New York, with $2,074 and $2,062, respectively.

Pennsylvania had the lowest number of state and local workers per 10,000 residents: 380.6. It paid them an average of $1,745.

Mississippi paid the lowest average monthly salaries, at $1,187, and had 518.4 workers per 10,000 residents.