Formaldehyde (HCHO) is one of the main pollutants of indoor air. Exposure to excessive formaldehyde for a long time will cause serious damage to human eyes, skin and respiratory organs, and even lead to loss of the function of nervous system［1］, as well as ear, nose and laryngeal cancer[2]. Therefore, a rapid, efficient and accurate detection of gaseous formaldehyde is of great significance to human health. So far, there have been a lot of techniques that can be used for the detection of gaseous formaldehyde, such as gas chromatography (GC)[3] and high-performance liquid chromatography (HPLC)[4]. Although chromatographic apparatus may provide detection limits of several μg·m-3, they are time-consuming and not suitable for real-time and continuous monitoring of formaldehyde concentration because of their weight and bulk. Semiconductor gas sensors based on gas-sensitive films provide a good alternative in indoor formaldehyde monitoring due to their advantages of high stability, short response time and continuous monitoring. However, high detection limit (>300 μg·m-3) and poor selectivity is considered to be a great limitation for such sensors[5]. Enzyme-based biosensors usually have a good sensitivity and selectivity, but their thermal stability is usually poor, which seriously restricts their application[6]. Colorimetric and fluorescence methods are widely applied in the design of formaldehyde gas sensors because of their fast response, high sensitivity, low detection limit, good selectivity, simplicity and low cost［7-9］. These methods are based on the combination of probes and formaldehyde which can generate new substances, resulting in the change of absorption spectrum or fluorescence enhancement, so that ones may achieve quantitative detection of formaldehyde. Descamps et al developed a portable formaldehyde detector by using 4-amino-3-penten-2-one (Fluoral-P) as a probe. Fluoral-P is a reagent with enaminone structure which can selectively react with formaldehyde to form cyclic compound 3,5-diacetyl-1,4-dihydrolutidine (DDL). Since the absorption band of Fluoral-P is far apart from the absorption band of DDL, and a fluorescence peak with large Stokes shift can be produced after combined with formaldehyde, it is widely applied for the detection of formaldehyde. However, Fluoral-P is extremely unstable and easy to hydrolyze to form acetylacetone and ammonia under the presence of water, which severely limits its application in formaldehyde detection[10].In this work, we have studied the optical and chemical properties of the interaction between 4-amino-1,1,1-trifluorobut-3-en-2-one(3F-FP), a derivative of Fluoral-P, and formaldehyde solution by UV-vis absorption steady state fluorescence spectroscopy and gas chromatography-mass spectrometry(GC-MS). We found that the hydrolysis rate of Fluoral-P is k＝1.555 9×10-5 L·mol-2·s-1, however, 3F-FP has very low hydrolysis rate(close to 0) and shows excellent stability in water environment. Meanwhile, 3F-FP can react with formaldehyde to form cyclic compound 6F-DDL, and a new absorption band appears at 430 nm and the fluorescence peak intensity at 489 nm also gets a significant enhancement and the enhancement factor is 12. The fluorescence growth rate is k＝7.881×103 h-1. In the following work, we will use porous glass as the carrier for 3F-FP[11], by which the concentration of 3F-FP and contact surface area between the 3F-FP probe molecule and formaldehyde can be increased, leading to further increase of the fluorescence growth rate. In conclusion, 3F-FP has shown good application prospects in the field of gaseous formaldehyde detection.