Abstract: Fuzzing and concolic execution are two important techniques in the area of binary analyzing and testing,and they are able to complement each other well.To find deep bugs in the code,a new path-recording approach was proposed to make concolic execution assist fuzzing.And the approach was implemented in a tool called Digger.The Digger was arranged to deal with target programs that require input from files or with extra arguments.The Digger was evaluated on an example program as well as real-world applications (e.g.,coreutils,catdvi,etc.).Experimental results show that by using the new path-recording approach,Digger can reach higher code coverage and find more bugs than a well-established tool,i.e.,Driller.