An analytic system of two stages cold trap enrichment and GC/FID for the determination of trace phosphine in environment was developed,using flame ionization detector （FID）.The influences of cold trap temperature,carrier gas flow,column oven temperature and detector temperature on the enrichment and determination for phosphine were investigated.At the same time,the mechanism of phosphine enrichment was also discussed.In addition,the system was used to measure mixture bound phosphine（MBP） in the typical paddy fields in Guangzhou.As a result,the best operation condition was defined as follows： cold trap temperature： -90 ℃,carrier gas flow：1.5 mL/min,column oven temperature： 90 ℃,and detector temperature： 220 ℃.The main mechanism for the cold trap enrichment was the enrichment capillary′s absorption to phosphine,belonging to gas-solid absorption.In the whole cycle of rice growth,the average concentration of mixture bound phosphine （MBP） was 120.59 ng/kg,with an average relative standard deviation（RSD） of 8.5%.With the detection limit of 0.041 7 pg and RSD of 4.3%,this system had a similar function for detecting phosphine to the traditional method with nitrogen phosphorus detector（NPD）.Owing to the simple constitution,easy operation and moderate price of FID,this system makes the analysis of trace phosphine easier,thus could be applied in lad generally.