By The Associated Press.

HAVANA, Feb. 23--Cuban rebels kidnapped Juan Manuel Fangio, Argentine world autoracing champion, from his hotel in downtown Havana at gunpoint tonight.

The unmasked men entered the lobby of the Lincoln Hotel while Senor Fangio was talking with three racing associates.  One man guarded the doorway.  The other walked up and stuck a pistol into Senor Fangio's back and ordered him out.

The five-time winner of the world's automobile racing championship was quickly bundled into a waiting automobile, which moved off at high speed.

The rebel movement led by Fidel Castro immediately announced its responsibility for the kidnapping.  A rebel spokesman telephoned news agencies and said Senor Fangio had been abducted by the rebels.  The Cuban refused to say what would be done with the driver.

The police started an intensive hunt for the kidnappers.  They assigned squads to guard the twenty-four other internationally known racing drivers here for Cuba's Gran Premio auto race tomorrow.

The 46-year-old world champion, a heavy favorite in the race, had just returned to the hotel after making the fastest trial run on the Malecon racing course in his Maserati car.  He was kidnapped at 8:55 P.M.

Nello Ugolini, director of the Maserati automobile manufacturing plant, said he and two others had been talking with Senor Fangio at the time.  The others were the champion's mechanic, Guarino Betochy, and Guerino Guerini, a racing driver.

Marcello Gambertone, who is Senor Fangio's representative in Cuba, was called by hotel employees after the racing champion had been abducted.  Senor Gambertone then informed the police.

The police and the National Sports Commission declined to discuss the champion's disappearance was being made in rebel haunts in Havana.

Rebel terrorists for the last three days have been circulating bulletins warning Cubans to stay off the streets and away from public spectacles.  They also hinted at bombings or other acts of sabotage and that a general strike possibly would be called shortly.

The rebels have been opposing big sports events, saying that the Government should instead be  concentrating on providing jobs for the 500,000 unemployed.

Supporters of Fidel Castro, the rebel leader, have been waging a fourteen-month-old campaign against the Government of President Fulgencio Batista.  Their drive recently has been stepped up, apparently in an effort to disrupt the Cuban election scheduled for June 1.

Most of the fighting and more violent outbreaks have been centered around the rebels' mountain stronghold in Oriente Province, but bombing and sabotage have extended across Cuba and into Havana itself.

Senor Fangio is a sports idol in his native Argentina.  He is widely known in Europe, having met and beaten European drivers on their home grounds.

In most of his triumphs during recent years he has driven an Italian-built  Maserati.  He originally was a member of the Maserati factory team.  When that company discontinued its sponsorship of a racing team last year, he drove privately owned Maseratis.

Senor Fangio, a conservative driver who knows just how to pace himself and his machine to wind up winner, won the twelve-hour Grand Prix of Endurance at Sebring, Fla., in 1955 and 1957.

There has been talk that he might enter the 1958 Indianapolis 500, which most foreign drivers pass up.  The men who ride the Grand Prix circuit with its twisting road courses drive cars that are not suited to a big oval track like the Indianapolis Speedway.

Senor Fangio, son of a plasterer who migrated from Italy to Argentina, began working in a garage when he was 11 and drove his first race at 23.