【Abstract】 Objective To explore the effect of “virtual laboratory(VL) flipped classroom” in teaching of virus infection diagnosis. Methods It was constructed the flipped classroom relying on the internet virtual lab platform of medical microbiology. 40 students of Class One from clinical medical undergraduates of grade 2014 were randomly taken as the experimental group

with 40 students of Class Two as the control group. The experiment group adopted flipped classroom by virtual lab platform and classroom activities

while the control group adopted tradtional classroom such as watching video

teaching. Finally post-test scores were compared by the independent samples t-test of SPSS 18.0 statistical software between the two groups. The teaching effects were evaluated through questionnaires survey in experimental group. Results The examinatal scores (82.73±2.62) of comprehensive assessments were superior to the control scores (57.94±4.65). Difference between the two groups was statistically significant (t=29.380

p=0.000). Students' satisfaction concerning the teaching methods and effects of the flipped classroom in experimental group was up to 85%. Conclusion Flipped classroom based on internet virtual lab platform in teaching of virus infection diagnosis can enhance the teaching quality

improve students' learning enthusiasm and thinking ability.