用热台偏光显微镜和ＤＳＣ法研究了含苯甲酸－４－甲氧基苯酯介晶基元和偶氮苯光色基元侧链共聚硅氧烷（ＰＳⅡ）的液晶性．将非介晶基元并入液晶均聚物ＰＳⅡ－１，共聚物ＰＳⅡ－２、ＰＳⅡ－３的液晶态类型不变，ＰＳⅡ－４仅存在近晶相，ＰＳⅡ－５～８无双折射现象，保持共聚物液晶性的最低含介晶基元单体的极限摩尔含量为８０％。在液晶共聚物中，非介晶基组分含量增加时，其Ｔ＿ｍ、ΔＨ＿ｍ和ΔＳ＿ｍ降低；非介晶组分在１０ｍｏｌ％时，Ｔ＿ｉ、ΔＨ＿ｉ和ΔＳ＿ｉ具有最小值。 The liquid crystallinity of the side chain polysiloxane (PSⅡ) containing 4-methoxyphenyl benzoate mesogen and azobenzene photochromic was studied by hot-stage polarizing microscope and DSC. The non-mesogenic units were incorporated into the liquid crystal homopolymer PSⅡ-1. The liquid crystal states of PS Ⅱ-2 and PSⅡ-3 remained unchanged. The PS Ⅱ-4 only existed smectic phase, while the PS Ⅱ 5-8 had no birefringence. The lowest molar content of mesogen-containing monomer that maintains liquid crystallinity of the copolymer is 80%. In the liquid crystal copolymer, the Tm, ΔHm and ΔSm decrease when the content of non-mesogenic component increases; while the non-mesogenic component has the smallest value at 10mol% T_i, ΔH_i and ΔS_i.