The development of the industrial world is increasingly rapid. Industry is a major source of environmental problems and contributes significantly to the depletion of natural resources, one of which is the use of natural sand. The use of natural sand continues to increase along with the increase in infrastructure development. So from these problems, an alternative fine aggregate is needed to save our environment. The solution that can be used is to use mining waste, one of which is nickel slag which is very large in many nickel producing countries in the world. This study aims to determine how much influence of nickel slag as a substitute for fine aggregate on the workability and compressive strength of concrete. Method used in the study was experimental, namely making a concrete mixture with cylindrical (15 x 30) cm test objects with a compressive strength plan of 20 MPa which would be tested at the age of 7, 14 ,28 and 56 days. Planning of concrete proportion mixture using mix design method of Indonesian Standard SNI 03-2834-2000.