The purpose of this study was to find out what important variables were involved in gambling behavior. The variables were divided into three parts: family variables, school variables and personal variables. 
                The sample consisted of 432 Mathyom Suksa 1-6 male students (216 lower secondary students and  216 upper secondary students) 
              The instruments used were background questionaire, gambling behaviors questionaire, bringing up test (love-oriented, reasoning-oriented and control-oriented), friends' influence acception test,leisure time spending test, psychological scarcity in school test, internal-external locus of control test, gambling attitude test. 
               Statistical techniques used in this study were two-way ANOVA, three-way ANOVA using Scheffe for multiple comparisons and Multiple  Regression. 
               The findings revealed that: 
                1.  Students whose close persons with gambling behaviors were  few,  whose perception of psychological scarcity in school was low, whose acceptance of friends' influence in a bad way was low, who spent  their leisure time appropriately more, who had high academic achievement, who had in gambling, had significantly less gambling behaviors. 
                2.  Students who were brought up in moue reasonable ways and had few close gambling persons had significantly less gambling behaviors than the ones who were brought up in less reasonable ways and had more close gambling friends. 
                3.  Students who accepted friends' influence in a bad way less and spent theis leisure time appropriately more had significantly less gambling behaviors than the ones who accepted friends' influence in a bad way more and spent their leisure time appropriately less. 
                4.  Family variables, school variables and personal variables could predict gambling behaviors up to fifty four percent.