The free hydrocarbon and vacuum pyrolyzed hydrocarbon of Botryococcus are analyzed by GC-MS system. The free hydrocarbon is mainly composed of C

27

-C

33

alkenes

and also contains C

13

-C

25

n-alkane

C

15

-C

21

is oprenoid alkanes and trace sterane and terpane as well. The pyrolyzed hydrocarbon is C

13

-C

36

n-alkanes

C

15

-C

21

is oprenoid alkanes

sterane and terpane. The author considers that the hydrocarbon of Botryococcus bearing Neogene mudstones in Gudong Region

Shengli Oilfield in Shandong

are generated by Botryococcus.