This study was designed to investigate the effect of aerobic exercise on the brain waves and automatic nervous systems according to the time zone of the exercise. To this end, the difference according to the time of exercise was compared by dividing 18 male college students in their 20s into morning exercise group (9 persons), and evening exercise group (9 persons). An aerobic exercise program (walking, running) was carried out for 8 weeks. The exercise intensity was set to 60 to 70% of the maximum heart rate, and exercise awareness to 11 to 13 using a polar heart rate monitor. Before and after exercise, alpha waves were measured in prefrontal lobe(Fp1, Fp2), frontal lobe(F3, F4), temporal lobe(T3, T4), parietal lobe(P3, P4) for three minutes using an EEG checker (QEEG-LEX3208) in accordance with international 10-20 system of electrode placement, and measure brain waves were analyzed using data acquisition software (Telescan). For inspection of automatic nervous system, an automatic nervous system analyser (SA-3000P) was used, and measurement lasts for five minutes, and time zone area(Mean HR, SDNN, RMSSD) and frequency domain (TP, LF, HF) were measured. For processing data, a comparison was made by calculating the mean and standard deviation of each variable using SPSS statistics software version 20.0 for Window users. The repeated measures analysis of variance was carried out to compare automatic nervous system variables and changes in brain waves before and after 8 weeks of aerobic exercise between groups (morning exercise group, evening exercise group). The significance level for processing of all statistics was determined at a=.05.

1) Changes in brain waves according to the timze zone of exercise

(1) The alpha waves of the left and right prefrontal lobe according to the time zone of exercise showed no signifiant difference between groups (p>.05), but there was a significant difference between the time (p<.05).
(2) The alpha waves of the left and right frontal lobe according to the time zone of exercise showed no significant difference between groups(p>.05), but there was a significant difference between the time(p<.05).
(3) The alpha waves of the left and right temporal lobe according to the time zone of exercise showed no significant difference between groups(p>.05), but there was a significant difference between the time in the left temporal lobe(p<.05).
(4) The alpha waves of the left and right parietal lobe according to the time zone of exercise showed no significant difference between groups(p>.05), but there was a significant difference between the time in the right parietal lobe(p<.05).
2) Changes in automatic nervous systems accoring to the time zone of excercise

(1) The average heart rate according to the time zone of excercise showed no significant differences between groups (p>.05), and there was no significant difference between the time (p>.05).
(2) The SDNN according to the time zone of exercise showed no significant difference between groups(p>.05), and there was no significant difference between the time(p>.05).
(3) The RMSSD according to the time zone of exercise showed no significant difference between groups(p>.05), and there was not significant difference between the time(p>.05).
(4) The TP according to the time zone of exercise showed no significant difference between groups(p>.05), and there was no significant difference between the time(p>.05).
(5) The LF according to the time zone of exercise showed no significant difference between groups(p>.05), and there was no significa수 difference between the time(p>.05).
(6) The HF according to the time zone of exercise showed no significant difference between groups(p>.05), and there was not significant difference between the time(p>.05).

The summary of the above results found that there was a significant increase of alpha waves in the left and right prefrontal lobe, left and right frontal lobe, left parietal lobe and right temporal lobe. However, there was no significant difference in the automatic nervous system (the average heart rate, SDNN, RMSSD, TP, LF, HF). It turned out that the aerobic exercise is effective in changing alpha waves of male college students, and there was no differences by the time zone of exercise. Accordingly, it is required to conduct regular aerobic exercise according to the individual''s lifestyle to ensure effective changes in alpha waves.