Abstract: Abstract: It is important to study the factor of clogging of emitter, which is the prerequisite for drip fertigation technology to be used and promoted in Yunnan red loam. In this paper, we chose three different irrigation emitter types (drip irrigation belt embedded with inner patch, 2-hole flow adjustable emitter and 8-hole flow adjustable emitter) as study subject under the water quality condition combined with three fertilization concentrations (0, 0.6 and 1.2 g/L) and three sediment particles size range were applied on root area infiltration irrigation and surface drip irrigation. The irrigation experiment of 5 min each time was conducted under working pressure of 20 kPa for three days. The difference in weight of the flowerpots before and after irrigation was the amount of water irrigated. After the experiment, the irrigation amount of emitters was recorded. If the relative flow rate of emitter was below 75%, the test stopped and then recorded effective irrigation times. The results showed that there was a very significant interaction between the soil particle size and emitter types, fertilizer concentration and emitter types, irrigation types and emitter types (P＜0.01), but there was no significant interaction between them (P>0.05). The bigger Yunnan red loam particle size, the easier clogging was made on flow adjustable emitter. Such as 2-hole flow adjustable emitter on surface drip irrigation，when the application rate of fertilizer was 0 g/L, the effective irrigation times of muddy water with three different particles size range were 11, 8 and 5, respectively. As for drip irrigation belt embedded with inner patch, Yunnan red loam particle size ranging 0.0385 - 0.074 mm was the easiest to cause clogging and the particle size ranging 0 - 0.0385 mm was the least to cause clogging. The fertilization has a significant influence on the clogging of the emitter. When the fertilizer concentration was less than 0.6 g/L, the large impact of fertilizer application on emitter was most obvious. When the fertilizer concentration was more than 0.6 g/L, the number of effective irrigation times did not have obvious change. However, the trend of the relative flow rate of the emitter increased, indicating that the blockage of the emitter increased. The irrigation type was an important factor affecting the clogging of emitter and it had different effects on different emitter. For 8-hole flow adjustable emitter, the anti-blocking performance of the surface drip irrigation was better than the root area infiltration irrigation. Under the surface drip irrigation, when the application rate of fertilizer was 0, the total effective irrigation times with three different particle sizes were four times more than root area infiltration irrigation. When the application rate of fertilizer was 1.2 g/L, the total effective irrigation times with 3 different particle sizes were 18 times and the root area infiltration irrigation were 15 times. For 2-hole flow adjustable emitter and drip irrigation belt embedded with inner patch, two different irrigation types did not have abviously different for effective irrigation times. Under the condition of fertilizing in muddy water, the performance of different emitter on clogging was different. The most clogged emitter was 8-hole flow adjustable emitter, followed by 2-hole flow adjustable emitter and the last was drip irrigation belt embedded with inner patch. This paper provides a theoretical basis for the application and familiarization of drip fertigation technology in Yunnan red loam.