中文摘要：

二十世纪六七十年代强子结构研究的进展使人们认识到了亚核子——夸克——的存在。随后,实验和理论上关于夸克之间作用渐近自由性质的发现使学者们明确地提出了“夸克物质”的概念。理论上预言的这种物质是否真的存在将在很大程度上检验目前基本强作用的理论。夸克星就是夸克物质的可能存在形式之一,相关研究也是人们探索超核密度物质状态的重要途径。该文简述脉冲星、中子星及夸克星的研究历史,总结了近年来夸克物质与夸克星研究的重要成果,指出了夸克星与一般中子星的异同以及若干夸克星候选体。

英文摘要：

During the 1960s and 1970s,hadrons were suggested to have substructures,i.e. quarks.In the 1970s,asymptotic freedom was found in deep inelastic scattering experiments and soon proved by theory,which inspired the idea of quark matter.Does quark matter exist？ To prove the existence of quark matter or not will put considerable constrain on current theory of strong interaction.Quark star is one of the possible existences of quark matter.Studying of quark star is an effective way to understand superanuclear physics.The history of pulsar, quark star and neutron star is briefly reviewed in§1.We introduce the development of quark star theory in the early stage and the recent development of color-superconducting.The relation between pulsar,neutron star and particle physics is also presented.The difficulties to distinguish quark stars and neutron stars are mentioned.In§2,we present phenomenological description of quark matter.Phase diagrams considering color-superconducting and quark-clustering are shown.Possible color-superconducting phase such as color-flavor locked phase and two-flavor color-superconducting phase are discussed.The highly non-perturbation property of quantum chromodynamics and the difficulty in lattice quantum chromodynamics are discussed.Possible evidences for quark matter from heavy ion collider experiments are mentioned.In§3,we summarized the general properties of quark stars and their differences from neutron stars,including the surface electron layer,the idea of bare quark star,the mass-radius relation,and the upper limit of spin period.Recent research progresses in the study of quark star are summarized in§4 and§5.Possible ways to distinguish between quark star and normal neutron star are discussed,i.e. by featureless spectrum,low mass and small radius,and spin period less than 0.5 millisecond. Several quark star candidates are suggested,i.e.the accretion-driven millisecond X-ray pulsar SAX J1808.4-3658,RX J1856-3754 which has quite good featureless black body spectrum, and PSR B0943＋10 wh