This study aimed to clarify factors affecting the conservation activities of Satoyama landscapes of suburban areas，employing a two-phase model of pro-environmental behavior (two-phase model). Shiroi city，Chiba，was taken a case study area to conduct a questionnaire survey targeting at residents of and those involved in a conservation organization. Factor analysis was employed to explore the constructs underlying conservation activities. Then，factor scores of the constructs were used for structural equation modeling to analyze how each construct influence each other. The analysis revealed that 1) the perceived seriousness of environmental problems and the belief in the effectiveness of a pro-environmental lifestyle had a significant influence on goal intention，2) cost-benefit evaluation and social norm evaluation had a significant influence on behavior intention，and 3) goal intention had a significant influence on behavior intention. The cost-benefit evaluation was the most influential factor on the behavior intention among others，followed by social norm evaluation，belief in the effectiveness of a proenvironmental lifestyle，and perceived the seriousness of environmental problems. In addition，Wilcoxon signed-rank test revealed that people over 60 and those who have an experience in Satoyama landscape conservation had significantly higher factor scores in the majority of factors，including goal intention and behavior intention.