There have been some reports on liquid core optical fiker(LC0F) spectrophotometr[ 1,2], but refractive-index of liquid must be more than 1.46. This paper presents new types of LCOFs filled with low refractive-index fluid or aqueous solution(n>1.346), and measures their transmission and spectrum. ConstructiB of LCOF and making solution as core are introduced. Based on this the LCOF spectrophotometry is developed and sensitivity reach ng/ml. EXPERIMENTAL In figure 1, halogen lamp was used as light source(25Ow/24v). Y-type optical fiber divided radiation into two light beams: one coupled into LCOF looped 15cm in diameter, another into reference optical 3iber to eliminate the unstability of light source. light output from LCOF was detected with silicon PIN. Figure 2 shows the structure of LCOF. Opt~cal fiber(0.d. 60Opm) was inserted into hollow fiber(i.d. 8 0 pm, 0.d. 1.6" and through the space the liquid was introduced into hollow fiber by using of peristaltic pump and T connector. The introduction take less than lmin. to get transmission intensity stable for lm-long LCOF. This system had coupling loss 1 ldl3, withstand pressure 4Opsi and is convenient to disassemble or reassemble. THe alcohol are GR and the rest solvents are AR. R