Ofsted said it is concerned about Weston Lullingfields Primary School, near Baschurch.
Martin Spoor, lead inspector, said children are not as advanced with key skills such as reading.
He said: “Weston Lullingfields CofE School continues to be a good school. However, inspectors have some concerns that standards may be declining.
“Pupils thoroughly enjoy their time at school. The school lives up to its motto of feeling like a big family.
“However, pupils do not get off to the best possible start academically.
“Teachers do not plan their learning as well as they should. Work does not build precisely on what pupils can already do.
“The most able pupils would sometimes enjoy a stiffer challenge. Staff know the importance of early reading but the teaching of phonics and the encouragement for pupils to read need significant attention.
“Pupils benefit from a broad curriculum. Teachers often draw well on the local area or pupils’ own experience to make lessons more engaging. Trips to places of interest help to bring learning to life.
“Pupils enjoy a good range of activities outside the classroom, such as chess, karate and crafts.
“The newly appointed headteacher has an excellent understanding of the work to be done. She has written long-term plans that are helping teachers to plan pupils’ work better.”
Mr Spoor added: “Pupils do not learn to read as easily as they might do.
“Teaching does not present letters and their sounds in a clear and consistent way.
“Adults sometimes fail to notice pupils’ misunderstandings and so do not help them to learn from their mistakes.
“Those who fall behind receive effective support from staff and adult volunteers. In recent years, all pupils have passed the phonics screening check at the end of Year One.
“The school does not provide some pupils with reading books that are well matched to their abilities. The encouragement for pupils to read at home is half-hearted. Some pupils told us that they love reading, some said not.”