Objective To explore the effect of improving formative assessment inside classroom in the undergraduate education of anesthesiology by means of mobile application program (APP) based on in-ternet platform. Methods 195 students of the department of Anesthesiology first received conventional method (control group) and then received APP based on internet platform method (experimental group). In the control group, paper cards were used for in-class test and attendance rate was calculated by roll call. The experimental group used mobile APP to scan two-dimensional code for in-class test and calculated attendance rate. Afterwards, the implementation effect of formative assessment in classroom was compared between the two groups. Results The time-consuming of class-room test and score analysis in experimental group were lower than that of the control group (1.2 min/course hour vs. 18 min/course hour,6 min/course hour vs. 56 min/course hour). The attendance rate and score of test had no significant difference (98.3% vs. 100%, 17.2 vs. 17.5). The questionnaire survey showed students were satisfied with the new teaching method (98.5%) because of its convenience (100%), objectivity (97.4%), feasibility (98.5%), less workload (100%), enthusiasm stimulation (97.4%), and better teaching effect (100%) in experimental group. Conclusion The mobile application program (APP) based on internet platform is a convenient, accurate and objective method which has positive effects to improve formative assessment inside classroom in undergraduate education of anesthesiology. It is a new scientific and low-cost teaching method, which deserves further promotion.