CO

2

/

3

He ratio of the mantle-derived CO

2

gas pools ranges from 10

7

to 10

13

in petroliferous basins in East China.This differs greatly from the constant CO

2

/

3

He ratio of 2?10

9

-7?10

9

of the manile-derived CO

2

gas while Separatng from the basalt magma. The CO

2

/

3

He ratio of Wanjingta CO

2

gas pool formed in Mesozoic in Sogliao Basin ranges from 10

9

-10

13

but that of the mantle-derived CO

2

gas pools formed since Cenozoic in Huangha

Jiyang

Subei and Shanshui Basins is as low as 10

7

-10

9

. This indicates that CO

2

/

3

He ratio of the mande-derived gas pools is controlled by release mechanism of the gases.The eruption and intrusion of the basalt magma provided a large number of gas sources for the formation of the mantle-derired gas pools; the CO

2

gas in the magma chamber would release directly along fault-passages which cut the chamber deeply. This played an important role in the formaion

the gas source supplies

the CO

2

/

3

He ratio and geochemical properties of the pools. Meantime

characters of CO

2

/

3

He ratio of the inomanic origin CO

2

gas pools provide a new evidence for its mantle-derived origin.