After agricultural products were incorporated into the WTO multilateral trade regulations， the role of tariff and other traditional trade protection measures has declined. On the contrary， sanitary and phytosanitary(SPS) measure， which closely relates with food safety， health of animal and plant， and environmental safety， has become the prior policy tool for most governments. Theoretically speaking， SPS measure may become a trade barrier by increasing exporters’ cost of compliance. But it may also act as trade catalyst by increasing transparency， reducing the asymmetry information and preventing the risks. The literature on the effects of SPS can be divided into two groups: one group considers SPS measure as a trade barrier， while the other group supports it as a trade catalyst． There are some defects in the previous research. First of all， the objects of the studies are limited to certain countries or groups or confined to specific products， so that it is hard to truly evaluate the effects of SPS measure on the trade of the overall agricultural products. Secondly， they approach the effects of SPS measure on trade from the exporters’ perspective， ignoring the effects of trade diversion causing by SPS of the importers. With China having become a major player in the world trade， especially with China having become the world’s largest importer of agricultural products， the impact of SPS measure on the import of agricultural products deserves much research attention. It will provide a reference for China to adopt SPS measure effectively by studying the cases in the developed countries.  The contribution of this paper lies in the following aspects. （1） Approaching from the angle of importing countries， it has studied the impact of SPS notification in each chapter of 24 chapters （HS01-24） of agricultural products on the import of goods in that chapter， by using the data from four developed countries， i.e. United States， Canada， Japan and Australia， and has taken into consideration the effects of trade division that have been ignored in previous studies. （2） It has found that the impact of SPS measure on the import of agricultural products forms a U-shape， which shows the SPS measure restricts the imports in the first two years of the implementation， but it promotes the import later. （3） It has revealed that the SPS measure has different effects on primary agricultural products （HS01-14） and the processed agricultural products （HS15-24）， which explains the reason why the scholars have drawn different conclusions about the effects of SPS measure in their previous studies. The studies that involve the primary agricultural products consider SPS measure as a trade barrier， while the studies that involve the processed products consider it as the trade catalyst.  The conclusion of our research provides policy implication for the countries including China to implement SPS measure. As an exporter， a country need to shorten the time of compliance with SPS measure by investing in the infrastructure， and continuously improving the quality of agricultural products， as well as minimize the adverse effects of SPS measure by adjusting the export structure of agricultural products and exporting more processed agricultural products. As an importer， a country has better to develop different SPS measures for the primary and processed agricultural products respectively， and keep adjusting and updating SPS measures to improve the protection of domestic residents， plants and animals， and environment．