<p> One of the characteristics of Mashiki Earthquake, which occurred in April, 2016 is that many people evacuated their homes because countless aftershocks followed the main shock. The aim of this study is to indicate quantitatively the amount of outdoor evacuation, by comparing aerial pictures taken before and after the earthquake in the center of Mashiki, which was badly affected by the earthquake, and by analyzing the changes in outdoor parking distributions.</p><p> The analysis subjects are 130 open spaces where more than five vehicles were confirmed to be present after the earthquake. Four pictures were used for comparison: one taken before the earthquake in December, 2015; one on 15 April, 2016 after the foreshock; one on 16 April after the main earthquake; and lastly on 30 April, which was two weeks after the main earthquake. In addition, a field survey was conducted to investigate the attributes of open spaces and the number of vehicles parked there in February, 2018.</p><p> After examining the number of vehicles parked at publicly owned and privately owned open spaces after the disaster as an overall trend, it was found that the number of vehicles increased in the former, but only small changes were found at the latter. The increased number of vehicles in public spaces was confirmed not only in the evacuation areas, but also in parks, parking lots at public facilities, and unused land.</p><p> Furthermore, the correlation was analyzed between the open space attributes and the number of parked vehicles using quantification method I. As a result, it was found that some conditions, such as road connections or pavement conditions, affected people’s choice of evacuation parking spaces, and the number of parked vehicles increased in the publicly owned grounds which were easily seen and had easy motorway access.</p><p> As a result, three points were clarified:</p><p> 1) When comparing the number of vehicles parked in publicly owned open spaces before the earthquake, after the foreshock, and after the main shock, the vehicle numbers increased consecutively. However, the degree of increase differed according to the usage of the open space.</p><p> 2) When comparing the three above time points in the case of privately owned ground, the range of increase in the number of parked vehicles was small. Also, this site type showed the least increase in the number of parked vehicles after the main shock.</p><p> 3) As for the relationship between the open space attributes and the number of parked vehicles, difference in the attributes was only seen in the open space in the publicly owned open sites, and the existence of easy motorway access from the open space was the main factor in the choice of evacuation parking location.</p>