DES MOINES, Iowa (AP) _ Iowa Democrats voted Saturday to compile a limited ''body count'' of party activists who attend next February's precinct caucuses to show which presidential candidate they support.

The vote by the party's State Central Committee drew criticism from news organizations which wanted more detail on the results of the caucuses, the 1988 campaign's first test of presidential strength in the Democratic Party.

''It's not what we wanted to hear,'' said Bob Flaherty, executive director of the News Election Service, which tabulates election results nationally.

The dispute has been closely watched because interpretation of the Iowa caucus results will have a strong influence on the primary campaign season determining Republican and Democratic presidential nominees.

Under the plan approved on a voice vote Saturday, party officials said they would tabulate the number of caucus-goers who support presidential candidates, but only candidates who are backed by at least 15 percent of the party members at a caucus will be considered.

In addition, the Democrats said they would tabulate the number of delegates each candidate wins during the caucuses, as they have in past years.

On Feb. 8, 1988, before any other state has an election showdown, Iowa Democrats will gather in church basements, living rooms and other places in each of more than 2,500 precincts across the state to begin the complex process of choosing their 58 delegates to the national convention. Some 100,000 people are expected to turn out.

Iowa Republicans will hold precinct caucuses the same night, but their procedures are not in dispute with the media because they call for a simple straw poll at the beginning to show candidate support.

Under the plan approved by the Democrats Saturday, backers of candidates receiving less than 15 percent support in the precinct caucus would either select another candidate or list themselves as uncommitted.

After the realignment, a second head count taken to determine how many delegates each candidate receives would be reported to the media. The first tally would go unreported unless reporters were stationed in each precinct.

The plan is a compromise between party factions who wanted to make no changes in the counting procedure and news organizations who sought a report on the initial head count. In past caucuses, even the second head count at each caucus was not tabulated statewide.

Critics of the plan warned that the party was changing its process for the convenience of news organizations.

''We're changing our process from a caucus to a straw poll,'' said committee member John Roehrick. ''I don't think, as a party, we can countenance that.''

Others, however, said much of the impact of the caucuses comes from heavy news coverage, and argued for tabulating all possible results.

''It adds additional credibility to us as a party,'' said Judy Wilson, a former Polk County Democratic chairwoman.

In addition to tabulating the limited ''body count,'' party staffers said they would help NES in locating tabulators in precincts around the state.