A District of Columbia trade show scheduled for Oct. 9 through 15 in Peking has been postponed because D.C. officials misjudged the amount of time needed to put it together, Deputy Mayor for Economic Development Curtis McClinton said yesterday.

No new date has been set for the show, which was to be a reciprocal event to last October's Economic and Trade Exhibition of Peking at the Washington Convention Center.

"Unfortunately, we misjudged the amount of time and planning required to duplicate the quality and success of the '85 show," McClinton said in a prepared statement.

The trade shows, arranged as part of a sister city agreement signed in May 1984 by Mayor Marion Barry and Peking Mayor Chen Xitong, were intended to foster increased trade between the two capitals. McClinton said yesterday the Peking show here last fall generated more than $61 million in business agreements between Chinese and U.S. concerns.

At the time of the Peking show here, city officials said the reciprocal show would be held in Peking this spring.

However, city officials said, the date was changed to October to allow for planning. The October date, McClinton said yesterday in an interview, proved unrealistic.

Courtland Cox, a D.C. economic development official involved in planning for the events, said that D.C. planners have concluded that a show of the magnitude envisioned by District officials requires at least 18 months of preparation.