The five-day game faces competition from the Twenty20 version, whose growing popularity is reflected in the success of the Indian Premier League and the World Championship.
David Morgan, the ICC president, said it was imperative to make Test cricket more exciting.
"We are examining is whether Test match cricket can be played over four days rather than five," Morgan told India Today magazine. " I would be very surprised if within a year you haven't seen some significant changes in Test match cricket."
Morgan also said the ICC was considering having day-night Tests with colored balls. "We need better over-rates, better pitches that give a good balance between bat and ball and we need to consider day-night Test cricket," he said.