We present a study on the physical properties of compact star-forming galaxies ( cSFGs ) with M _ { * } \geq 10 ^ { 10 } M _ { \odot } and 2 \leq z \leq 3 in the COSMOS and GOODS-S fields . We find that massive cSFGs have a comoving number density of ( 1.0 \pm 0.1 ) \times 10 ^ { -4 } ~ { } { Mpc } ^ { -3 } . The cSFGs are distributed at nearly the same locus on the main sequence as extended star-forming galaxies ( eSFGs ) and dominate the high-mass end . On the rest-frame U - V vs . V - J and U - B vs . M _ { B } diagrams , cSFGs are mainly distributed at the middle of eSFGs and compact quiescent galaxies ( cQGs ) in all colors , but are more inclined to ‘ ‘ red sequence ’ ’ than ‘ ‘ green valley ’ ’ galaxies . We also find that cSFGs have distributions similar to cQGs on the nonparametric morphology diagrams . The cQGs and cSFGs have larger Gini and smaller M _ { 20 } , while eSFGs have the reverse . About one-third of cSFGs show signatures of postmergers , and almost none of them can be recognized as disks . Moreover , those visually extended cSFGs all have lower Gini coefficients ( Gini < 0.4 ) , indicating that the Gini coefficient could be used to clean out noncompact galaxies in a sample of candidate cSFGs . The X-ray-detected counterparts are more frequent among cSFGs than that in eSFGs and cQGs , implying that cSFGs have previously experienced violent gas-rich interactions ( such as major mergers or disk instabilities ) , which could trigger both star formation and black hole growth in an active phase .