The formation of NaAlCO

3

(OH)

2

in the. Hailar Basin was related to CO

2

Pressure

and all NaAlCO

3

(OH)

2

-bearing wells are distributed in high value areas of CO

2

pr essu re. Bu t it is a fact that not all CO

2

reservoirs contain NaAlCO

3

(OH)

2

since CO

2

is just one of the factors to form this minerals.The CO

2

in the basin is of inorganic genesis and was dominated by Yenshan magmatic activity while magmatic activity impelled organic matter to matuate and evolute. Accoriding to the coexisting relationship between CO

2

NaAlCO

3

(OH )2 and hydrocarbon

and the distribution of NaAlCO

3

(OH)

2

target areas of oil and gas as well as CO

2

exploration could be predicted.