Soviet Ambassador Anatoliy Dobrynin returns here this weekend amid continuing rumors in Moscow and Washington that he might be replaced after the November summit meeting between President Reagan and Soviet leader Mikhail Gorbachev, according to diplomatic sources in both capitals.

After the surprise appointment of Eduard Shevardnadze as Soviet foreign minister in July, speculation was that Dobrynin, 65, might not return to Washington when his annual summer vacation concluded.

The rumors increased after news reports that Yuli Vorontsov, Soviet ambassador to France, had implied in a conversation that he would be moving to the United States.

Last month, however, authoritative sources in Moscow said Dobrynin would return here to help in preparations for this month's meeting between Reagan and Shevardnadze and the summit in Geneva Nov. 19-20.

These sources also said Dobrynin, whose 23 years in Washington mark him as one of the Kremlin's most astute "Amerkanisti," might stay on if, based on the Geneva talks, any agreements required further work or completion. After that, however, these sources said the future was unclear for the widely respected diplomat.

American Kremlinologists had long viewed Dobrynin as a logical successor to longtime Soviet Foreign Minister Andrei Gromyko. Speculation now has centered on his returning to Moscow as a deputy foreign minister.

One former Soviet colleague of Dobrynin suggested that Dobrynin might even remain here as ambassador.

This diplomat recalled that in 1971, Dobrynin called together the embassy staff here and announced that he would be returning to Moscow "after some matters had been cleared up" with the Nixon administration.

The subject was never brought up again, the diplomat said.