Six weeks before the promised Soviet withdrawal of all troops from Afghanistan, members of the Kabul government have moved dependents to new homes near the Soviet border, Western diplomats said Tuesday.

The diplomats also said the country's ruling Peoples Democratic Party is changing its name and that of its newspaper in an effort to broaden its appeal and remove references to the bloody 1978 revolution it rode to power.The moves coincide with the exodus of Soviet civilian advisers from the Afghan capital and warnings from foreign embassies that their nationals leave the country unless they have essential business, the diplomats said.

Under U.N.-mediated accords, half of the roughly 100,000 Soviet troops that had been in Afghanistan fighting Moslem guerrillas left the country by Aug. 15 and the balance are to be out by Feb. 15.

Soviet troops intervened in Afghanistan to prop up the government in 1979.

In the western part of the country, the Soviet pullout has begun from Shindad and Herat, said the Islamabad-based diplomats, who spoke on condition of anonymity. They quoted Afghan officials as saying the main military withdrawal will begin Jan. 15.

The diplomats said senior members of the Peoples Democratic Party of Afghanistan have been allocated apartments in Mazar-e-Sharief, 165 miles northeast of Kabul. Most of them have sent their dependents and household goods to a town near the Soviet border.

The Special Guard, which protects party and government officials, has increased to at least 4,000 members and is expected to rise to 20,000 to withstand guerrilla attacks when the Soviets leave, the diplomats said.

Special Aeroflot flights have taken Soviet advisers from the capital, and the Soviet Embassy has been reduced to about 100 workers, the diplomats said.

The ruling party will change its name to the Liberal, Democratic and National Party and adopt "free market policies along the lines of Western Social Democratic parties," said one Western diplomat, citing Afghan sources.

The name of the party newspaper has been changed from Truth of the April Revolution to the more moderate Message, diplomats said.

"The symbolism of junking the name of the (April 1978) revolution . . . is probably only the first in a series of steps designated to paper over the image of the (party) as a revolutionary communist party," another diplomat said.

A cease-fire President Najib offered on New Year's Day has been ignored by guerrillas and by government troops.