Objective: To study in vitro bacteriostasis of ethanol extract from the rhizomes of Zingiber striolatum Diels. Method: The rhizomes were percolated with ethanol and then the residue was sequentially extracted with petroleum ether

chloroform

ethyl acetate and n-butanol after reduce-pressure distillation. The ethanol extract and various polar fractions were screened for in vitro antibacterial activities by disc-diffusion method. The minimum inhibition concentrations (MICs) and minimum bacteriocidal concentrations (MBCs) were further determined for active polar fractions by broth microdilution method. Result: The crude ethanol extract (CEE)

petroleum ether-and chloroform soluble-parts (PE and CE

resp.) inhibited growth of Gram-positive (Staphylococcus aureus

Baicllus licheniformis and Streptococcus agalactiae) and Gram-negative (Escherichia coli

Klebsiella pneumonia and Pseudomonas aeruginosa) with MICs ranging from 312.5 mg · L-1 to 1 250 mg · L-1. The MBCs of CEE against B. licheniformis

S. agalactiae and E. coli were 1 250 mg · L-1

while those of PE and CE against all the test strains varied from 625 mg · L-1 to 1 250 mg · L-1. Conclusion: The CEE

PE and CE from the rhizomes of Z. striolatum possess antibacterial and bacteriocidal activities against S. aureus

B. licheniformis

S. agalactiae

E. coli

K. pneumonia and P. aeruginosa.