The minimum miscibility pressure（MMP） of CO

2

flooding is affected by crude oil components and reservoir temperature. And its influence rule has great significance to screen and evaluate gas injection reservoirs. The tie-line analysis is a method to calculate MMP analytical approach which is faster

more accurate

and easier to operate. In this paper

a calculation process of simulating CO

2

flooding by tie-line analysis was proposed

and the influence law of components（C

4

C

10

C

14

C

20

） and temperature on MMP was studied. The results showed that the simulation results of the tie-line analysis

were similar to those of the slim tube numerical simulation. The MMP increased with the increase of temperature

and the sensitivity of MMP for each component was more obvious in higher temperature. The MMP decreased with the increase of C

4

C

10

and C

14

components

but increased with the increase of C

20

component. The study proposed a new method with simple process and accurate calculation for calculating MMP and evaluating influencing factors.