This study aims to determine factors that affect surplus underwriting of tabarru‟ fund on Sharia Life Insurance in Indonesia. The factors used in this study is net contribution, claim expenses and investment return. This study used is panel data regression with Econometric Views (EViews) 8.0 as statistical analysis software. The samples are 14 Sharia Life Insurance, consists of 13 Islamic business units and 1 full sharia. During 2011 to 2015, the hypothesis test result showed the factors affecting surplus underwriting of tabarru‟ fund is net contribution, claim expenses and investment return always showed significant effect partially or simultaneously to the surplus underwriting of tabarru‟ fund on sharia life insurance.