Abstract: A catalyst for hydroisomerization with high isomerization selectivity and excellent stability has been obtained. For the advanced use of the catalyst in industry, the effects of reaction parameters such as temperature, pressure, space velocity and hydrogen to hydrocarbon H2/CH (mol ratio) on the catalytic performance of 0.4% Pt/SAPO-11 hydroisomerization catalyst have been investigated in a 10 mL fixed-bed down-flow reactor using n-heptane as a probe molecule. The catalytic behavior and the optimum reaction parameters have been thus obtained. The evaluation results manifest that the main reaction of n-heptane over Pt/SAPO-11 is isomerization, and the selectivity to i-C7 maintains above 90% even at the conversion up to 70%. The optimum reaction conditions are: temperature 360 ℃～380 ℃, pressure 0.5 MPa～1.0 MPa, WHSV 2.1 h-1～4.1 h-1, and H2/CH (mol ratio) 2～6. Moreover, the conclusion can be drawn from the obtained data that the reaction parameters interact with each other, indicating that variation of one parameter needs the adjusting others in order to gain an optimal performance.