Studies were carried out on a 31-gpt Green River shale sample to determine the effects of pressure, sweep-gas rate, and heating rate on the batch retorting process. Each experiment was performed in a vertical pressure retort which could be heated at predetermined fixed rates to a final bed temperature of about 950/sup 0/F. Nitrogen sweep gas was fed at the top and exited at the bottom along with any produced gaseous and liquid products. Sweep-gas rate and pressure were independently controlled. Pressures from atmospheric to 1,500 psig, nominal heating rates from 14 to 125/sup 0/F/hr, and sweep-gas space velocities generally in the range from 1 to 125 SCF/hr/ft/sup 2/ of bed were studied. Oil yields, gas yields, and the ultimate distribution of the initial organic carbon in the raw shale are reported for each run. Within the scatter in the data, pressure was the only variable that had an appreciable effect on the results of the retorting process. With increase of pressure, the oil yields (including C/sub 4/ gases) were found to decrease from an average of 93 percent (of Fischer assay) at atmospheric pressure to 78 percent at 1,500 psig. Other effects of increasing pressure were found to be an increase in gas production, an increase in retorted shale coke, a decrease in oil specific gravity and viscosity, and an increase in the amounts of lighter distillation fractions for the oil. A simple mathematical model was developed which accounts for the effect of pressure on oil yield. This model also gives oil production curves with time that are in reasonable agreement with measurements made during the current work. Some experiments were conducted using hydrogen sweep gas. Results of this work are also presented.