Objective: To study the antibacterial activity of Thladianthea dubia fruits in vivo and in vitro

and screen the extracts of antibacterial activity. Method: By methods of tube continuous dilution and agar plate diffusions to 14 strains of bacteria

for example Staphylococcus aureus

minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of different extracts of T. dubia fruits were determined in vitro . We chosen mice infected by the type strain of S. aureus 26002-6 as models to test the protection of the extracts of T. dubia fruits. Result: With regard to volatile oil of T. dubia fruits (VTDF)

the MICs to the type strains of S. aureus 26001-26

Staphylococcus aureus26002-6

Escherichia colt44102-3a3

S.albus 26069-5

Salmonella paratyphi A 50001-25

S.paratyphi B 50076-1

S.typhosa50071-10 were respectively 0.17

0.08

0.33

0.17

0.33

0.33

0.66 g·L-1

the MBCs were 0.17

0.17

0.33

0.33

0.66

0.66

1.32 g·L-1;and the MICs to the clinical-separated strains of S. aureus

Escherichia colt0415

E.colt0416

Enterococcus faecalis0318

Proteus mirabilis

Acinetobacter baumannii0207

S. pneumoniae 09030813 were respectively 0.66

0.66

0.66

0.66

0.08

0.66

1.32 g·L-1

the MBCs were 1.32

1.32

1.32

1.32

0.08

1.32

2.64 g·L-1. However

water extract and polysaccharides of T. dubia fruits (WTDF

PTDF) had antibacterial activity on partial bacteria in vitro . VTDF and PTDF might have obvious protective effect on infected mice induced by S. aureu

WTDF might have weak protective effect on infected mice induced by S. aureu . Conclusion: The antibacterial activity parts of T. dubia fruits are VTDF and PTDF.