The influence of four types of reactive dyes that are different in reactive group on silk fabric were investigated at three different temperatures, 5$0^{circ}C$, 7$0^{circ}C$, 9$0^{circ}C$ and the pH range from 7.0 to 11.0. The amount of absorption and fixation showed the optimum condition. The damage of silk during dyeing was determined by the change of physical properties. The results are given as follows: 1. The amount of dye fixed on fabrics at constant pH varied upon the reactivity of dyes. The affinity of dyes for silk fabrics were in order of Lanasol>Procion>Remazol>Cibacron. 2. The percentage of dye fixation on fabrics showed different tendency with temperature. The dye fixation of Cibacron and Procion was decreased above 7$0^{circ}C$ because of the influence of hydrolysis. The dye fixation of Lanasol and Remazol was increased with the increase of temperature. This showed that temperature did not affect on hydrolysis. 3. The tensile strength of dyed fabric decreased with increasing pH and temperature owing to high temperature and alkaline damage on silk fabric. 4. The optimum conditions of dyeing silk with reactive dyes were as follows: Cibacron -7$0^{circ}C$, pH 9.0, Procion-5$0^{circ}C$, pH 7.0, Remazol-5$0^{circ}C$, pH 8.0, and Lanasol-9$0^{circ}C$, pH 9.0.