The Inventory of Socially Supportive Behaviors (ISSB) appears to be a satisfactory measure of social support with good reliability and some evidence of validity. To investigate the dimensionality of the ISSB through factor analytic procedures and to predict social support from social network variables, 179 college students (97 male, 82 female) completed the ISSB and the Social Network List, which reflects the structure of a subject's social network in terms in size, number of people one feels close to ("Confide"), percentage of relatives, and density (proportion of network relatives to number of overall relatives). An analysis of the results suggested that the ISSB is an unidimensional measure and the total score obtained on the instrument can be used as a global measure of social support. The four major components of social support (emotional support, tangible assistance, cognitive support, and guidance) were measured by the ISSB. Of the network structure varibles studied, only Confide was linearly related to ISSB scores, and then only for males. This finding may reflect societal values regarding sex role socialization for males and females. (BL)