This paper proposes a hidden Markov model for the signal of U.S. recessions. The model uses the spread of interest rate between 10-year Treasury bond and 3-month Treasury bill, together with other financial indicators which are the real M2 growth, the change in the Standard and Poor's 500 index of stock prices, and difference between the 6-month commercial paper and 6-month Treasury bill rates as predictors. The hidden Markov model considers temporal dependence between the recession signals and provides an estimate of the long-term probability of recessions. The empirical results indicate the hidden Markov model well predict the signal of recessions in the U.S.