Two witnesses reported seeing Soviet President Leonid Brezhnev Monday, on one occasion entering the Kremlin Hospital and later being driven back to his country home just outside the city.

A Soviet woman, who asked that her name not be disclosed, said she saw the ailing, 75-year-old Soviet leader entering the hospital shortly before 10 a.m.

As the security police halted all traffic on Kalinin Street, the woman reported seeing Brezhnev being helped out of his limousine and then walking a dozen steps without assistance to the side entrance of the hospital.

A foreign resident reported seeing Brezhnev shortly before noon leaving the hospital in his Zil limousine. With all traffic again halted on Kalinin Street, the man reported, Brezhnev's limousine cruised slowly at about 40 mph, and he was clearly visible.

Brezhnev's automobile usually barrels through the city at about 80 mph.

The reports suggested that the Soviet leader's condition has improved considerably since his health "deteriorated seriously" during a visit to Uzbekistan last month. Well-informed Soviet officials said Brezhnev was taken on a stretcher from the airplane on his return from Uzbekistan, one of the Soviet Asian republics, March 25 and was hospitalized for an undisclosed ailment.

The Soviet leader has not been seen in public since leaving Tashkent, the Uzbekistan capital, March 25. He was reported to have left the Kremlin Hospital on April 4 and to be convalescing at his country home.

No photographs of Brezhnev have been published here during the past 20 days, but there have been rumors that his condition has improved considerably, although he remained under medical supervision.

Soviet sources said earlier that an exceptionally heavy schedule in March had led to a general weakening of Brezhnev's health and that was exacerbated by climatic and other changes on his four-day trip to Central Asia. The sources implied that he may have suffered a mild stroke aboard the plane carrying him from Tashkent to Moscow, but they insisted that he was not incapacitated.