A new method of imprinting lithography for processing paper based microfluidic chip was developed in this paper.The filter paper used in the study was soaked in the hexane solution containing alkylketone dimmer(AKD),and the triethanolamine solution was used as the blocking reagent.Painter software was applied to design chip pattern and make photosensitive stamp,which was then printed on the surface of the filter paper in accordance with the designed pattern.After the filter paper was heated in 105 ℃ oven for over 10 min,the non imprinted area was hydrophobic,and the imprinted area was hydrophilic.Thus,a liquid flow channel was formed.Influences of concentration of hydrophobic agent,selection and proportion of the blocking reagent and imprinted resolution on the property of paper based microfluidic chips were investigated.The prepared paper based microfluidic chips were used in colorimetric analysis of sodium nitrite solution,and a good linear relationship was obtained.Comprehensive experimental analysis results showed that,with low cost,simple operation and fast analysis,the method has a wide application prospect in production of inexpensive and easily popularized paper chips.