Objective      To investigate the characteristic parameters of acoustic startle reflex (ASR) during the acquisition of dual-task eyeblink conditioning (EBC)

and to analyze the effect of ASR on EBC.       Methods      Eighteen healthy male British albino guinea pigs were randomly divided into 3 groups

single-task delay eyeblink conditioning (DEBC) group (

n

=6); single-task t

race eyeblink conditioning (TEBC) group (

n

=6)

and dual-task group (

n

=6). Three groups received paired training of tone conditioned stimulus (CS) at different audio frequencies (3 and 1 kHz) and a 100 ms corneal oxygen-puff unconditioned stimulus (US). The characteristic parameters of ASR were observed in the 3 groups.       Results      There were significant difference between ASR% to 3-kHz-CS and ASR% to 1-kHz-CS in dual-task group (

F

=198.685

P

<

0.01)

and the former was significantly higher than the latter. Correspondingly

guinea pig showed a higher acquisition rate of TEBC to 3-kHz-CS. There was no significant difference between the ASR% of single-task DEBC group and the ASR% of single-task TEBC group (

F

=2.544

P

>0.05). The acquisition pattern of eyeblink conditioning of the 2 groups were accorded with other study’s results.       Conclusion      In the dual-task eyeblink conditioning

the ASR to low audio frequency CS will be inhibited by high audio frequency CS

and thereafter affect the learning of EBC which trained with low audio frequency CS.