The State Department is putting together a new package of $700 million to $800 million worth of military weapons and equipment for sale to Taiwan. The transaction would be the Reagan administration's largest military deal with the island nation off the coast of China.

The Peoples Republic of China would be certain to object to such a sale, U.S. officials acknowledged. But they maintained that it would be consistent with a joint U.S.-China communique signed last August, in which Washington agreed that its arms sales to Taiwan would not exceed "the level of those supplied in recent years" either in quality or quantity.

Officials said the arms and equipment list, being compiled primarily by the State Department with advice from the Pentagon, is expected to be ready within a couple of weeks for transmission to the White House. President Reagan will make a decision on the package and decide when to notify Congress about it.

Officials said they expect the package to include additional Chaparral anti-aircraft missiles (some of which are already in Taiwan's arsenal), anti-submarine warfare equipment, 155mm guns and other army and navy cannons, fire control equipment for the artillery and other electronic and test equipment. Some additional tanks, probably older M48 models, also could be included, but this has not been decided, officials said.

Earlier this fiscal year the administration notified Congress of its intention to offer for sale to Taiwan 357 old armored personnel carriers valued at $97 million. It also sold to Taiwan, for about $30 million, 66 aging F104 interceptors that had been used to train West German pilots here. In the communique of last Aug. 17 the United States also promised to "reduce gradually" its arms sale to Taiwan over a period of time.

Since then, however, China has sharply criticized the Reagan administration on several occasions, accusing it of "twisting the meaning" of the communique and exceeding the previous levels of arms supplies to Taiwan. China's new ambassador to this country repeated that accusation last week.

The Chinese are particularly suspicious of Reagan, who has long been a supporter of Taiwan. In an interview earlier this year, Reagan suggested an interpretation of the vaguely worded communique that differed from the Chinese interpretation.

American officials acknowledged that it is difficult to calculate precisely sales of arms to Taiwan under the language and formula agreed to in the communique. But they said they are trying to stay within the spirit of the communique in putting together the new package of arms for Taiwan, allowing for inflation and other higher costs.

The State Department recently announced that it was adding an index for inflation to the formula. This essentially would allow for the current higher value of the dollar. Officials also said that replacing equipment for Taiwan usually means more expensive equipment because some of the older versions of weapons or spare parts are no longer in production.

Officials said the list of military purchase requests from Taiwan is about twice as large as the projected forthcoming sale. Sales to Taiwan in fiscal 1982 totaled $600 million, and included the controversial approval for continued co-production of 60 F5E and F5F jets by Taiwan.