In　this　paper,　malonic　acid　was　tested　as　a　new　carbon　source　and　its　effects　on　the　structural　and　superconducting　properties　of　bulk　MgB2　have　been　systematically　investigated.　The　detailed　pyrolysis　process　of　malonic　acid　was　analyzed　to　understand　the　possible　doping　mechanism　of　malonic　acid　added　MgB2　samples.　The　weight　fraction　of　MgO　phase　and　the　actual　carbon　substitution　level　in　bulk　MgB2　increased　with　a　higher　amount　of　malonic　acid　addition,　which　was　proven　to　be　mainly　caused　by　the　reaction　of　Mg　and　CO2　gas.　A　moderate　amount　of　malonic　acid　addition　resulted　in　grain　refinement　and　enhanced　flux　pinning.　Bulk　MgB2　with　10　wt%　malonic　acid　addition　showed　much　higher　J(c)　values　in　the　entire　magnetic　field　range.　Three　different　doping　methods　with　the　same　amount　of　malonic　acid　addition　were　compared.　MgB2　samples　using　malonic　acid　and　ethanol　processed　boron　showed　the　highest　J(c)　value,　which　was　7.2　times　larger　than　that　of　the　pure　MgB2　at　20　K　and　5　T.