Abstract: Chang-8 oil reservoirs of Yanchang formation in Honghe oilfield are tight clastic reservoir,with low porosity and low permeability,it has the characteristics of complex pore structure,poor physical properties,strong heterogeneity,developed micro- porosity and high irreducible water saturation.Therefore,the fluid identification capability of resistivity logging is low.and there is frequent misjudgment phenomenon of low resistivity reservoirs and the water layers.In view of the tight clastic reservoir characteristics,based on logging data,by integrated use of testing,analysis and other geological data,the use of visual formation water resistivity ratio method,movable water analysis,nuclear magnetic resonance spectroscopy and other methods have been applied to carry out comprehensive study on fluid identification of Chang- 8 tight clastic reservoirs in Honghe oilfield and in the end,good results have been achieved.