The Haynesville, one of the most successful developed shale plays in the U.S., was used as a case in this study because of its important position, long history and complete database, based on which the production decline laws can be analyzed. The traditional Arps Hyperbolic and the modern Stretched Exponential decline curve models were applied to the well-by-well production data to find the characteristic parameters of production decline curves. The study shows: (1) most of the studied shale gas wells have a typical production pattern of peaking rapidly and declining steeply after the peak is reached; (2) during the decline phase, both the Hyperbolic model and the Stretched Exponential model fit well to the aggregate and the individual shale gas wells, even about 26% of the β-parameter values of the hyperbolic model are larger than one, which still can be used when a well life span is set as 20 years; (3) in the Haynesville play, about 70% of wells reach a peak production of 9.3×104~27.9×104 m3/d, newer wells tend to have higher peak production than older wells, and in the decline phase, the production decline rate after the first year is around 72% and over the first two years is around 86%.